Via Verde Santander-Mediterranea missing section between Soria and Zaragoza AI-pedia

The missing section of the Vía Verde Santander-Mediterráneo between Soria and Zaragoza is an unconditioned 43-kilometre gap in the trans-Iberian rail trail network. It follows the disused railway corridor of the historic Santander–Mediterranean railway (Ferrocarril Santander-Mediterráneo) from the provincial and regional border between Soria (in the autonomous community of Castile and León) and Zaragoza (in the autonomous community of Aragon) down to the city of Calatayud. While the sections immediately to the north-west in Soria and to the south in the Jiloca valley have been systematically converted into multi-use non-motorised trails, this stretch through the Ribota River valley remains in an abandoned state.

The corridor is owned by the Spanish national rail infrastructure manager, Administrador de Infraestructuras Ferroviarias (ADIF). Although the steel rails and wooden sleepers were removed between 1998 and 2003, the original coarse gravel ballast, engineering cuttings, embankments, stone viaducts, and decaying passenger stations remain intact. It forms a physical barrier that interrupts what is planned to be the longest continuous greenway in Spain, stretching over 500 kilometres from the Bay of Biscay in Cantabria to the Mediterranean coast of Valencia.

The persistence of this gap is primarily the result of administrative divergence between two regional governments, funding allocations by national ministries, and differing territorial priorities within Aragon. While the provincial government of Soria prioritised greenway development to the boundary line at Ciria, the regional and comarcal authorities in Aragon directed their initial resources toward the connection south of Calatayud to connect with the Vía Verde de Ojos Negros. As a result, long-distance cyclists, hikers, and local residents encounter an abrupt end to the conditioned trail at the regional frontier.

Historical Background: Line 106 (Calatayud to Cidad-Dosante)

The Ferrocarril Santander-Mediterráneo was conceived in the late 19th and early 20th centuries as a strategic direct trunk line connecting the northern industrial port of Santander on the Atlantic Ocean with the Mediterranean port of Sagunto and the broader Valencian agricultural basin. The project was intended to bypass the congested and circuitous railway hubs of Miranda de Ebro and Zaragoza, reducing transit times for heavy freight, mineral traffic, and passengers.

Under the dictatorship of General Miguel Primo de Rivera, the Spanish state approved a state-assisted concession for the route. In 1924, the Compañía del Ferrocarril Santander-Mediterráneo was incorporated, backed predominantly by British capital and Spanish railway engineers, notably Ramón de Aguinaga. Construction was divided into several geographical sections. Section 1 ran from Calatayud, where it established a junction with the Madrid–Zaragoza–Alicante (MZA) and Central de Aragón lines, northwest to the provincial capital of Soria, covering a distance of approximately 96 kilometres.

The Calatayud–Soria section opened for commercial operation in October 1929. The railway was engineered as a single, broad Iberian-gauge (1,668 mm) non-electrified line. The route required significant earthworks and stone masonry to climb from the Jalón and Ribota river valleys up through the Iberian System (Sistema Ibérico) onto the elevated Castilian meseta. Stations were built in a standardised regionalist architectural style, featuring limestone facades, hipped roofs, and complementary infrastructure such as goods warehouses, water towers, and residential quarters for railway staff.

Although the track from Calatayud through Soria and Burgos to Cidad-Dosante (a total of 366 kilometres) was completed by 1930, the northernmost extension through the Cantabrian Mountains toward Santander was never finished. The construction of the massive Engaña Tunnel (Túnel de la Engaña), measuring 6,976 metres, was stalled for decades and ultimately abandoned before tracks could be laid down to the coast. This left the line as a torso railway, terminating dead-end in the mountains of northern Burgos without reaching its primary maritime destination.

Despite this structural limitation, the Calatayud–Soria line functioned for over 50 years. It carried agricultural produce—particularly fruit from the Ribota and Jalón valleys, and sugar beets and grain from the Campo de Gómara—along with timber, postal cargo, and regular passenger services operated by steam trains, railcars (automotores), and omnibus trains. Following the nationalisation of Spanish broad-gauge railways in 1941, the line was absorbed into the state-owned railway network, RENFE (Red Nacional de los Ferrocarriles Españoles), designated as Line 106.

The 1985 Closure and Subsequent Abandonment

By the late 1970s and early 1980s, Spain's railway network faced mounting operational deficits, deferred maintenance, and intense competition from road transport. In September 1984, the Council of Ministers under Prime Minister Felipe González approved a national railway rationalisation decree. Under this contract-programme between the state and RENFE, lines operating below an arbitrary cost-recovery threshold (designated as líneas altamente deficitarias) were targeted for closure unless regional or provincial governments agreed to cover the operating shortfalls.

The regional governments of Aragon and Castile and León declined to subsidise the operations of the Santander–Mediterráneo line. Consequently, on 31 December 1984, regular passenger and general freight traffic were officially suspended. The final commercial trains ran on that date, and on 1 January 1985, the entire line from Calatayud to Cidad-Dosante was closed to traffic.

For roughly 15 years following the closure, the infrastructure sat derelict but largely intact. RENFE maintained nominal control over the corridor. In the late 1990s and early 2000s, the Spanish government authorised the lifting of the permanent way. Rail-stripping crews removed the steel rails, baseplates, and timber sleepers to recover scrap metal and salvage materials for other parts of the national rail network. This process stripped the route down to its underlying earthworks: the graded trackbed (explanación), drainage side-ditches, stone ballast, viaducts, and station yards.

The Rail Trail Programmes: Vías Verdes and Caminos Naturales

In 1993, the Spanish government initiated the Programa Vías Verdes (Greenways Programme), coordinated by the Spanish Railway Foundation (Fundación de los Ferrocarriles Españoles, FFE) alongside the national railway bodies RENFE and FEVE, and later ADIF. The initiative was designed to systematically transform abandoned railway corridors into non-motorised trails for pedestrians, cyclists, and people with reduced mobility.

Concurrently, the Ministry of Agriculture, Fisheries and Food (MAPA) established the Programa de Caminos Naturales (Natural Trails Programme). While the FFE provides brand governance, technical criteria, cartography, and promotional oversight, MAPA acts as the primary funding body and contracting authority for capital public works. Under this framework, local public entities—such as provincial councils (diputaciones provinciales), regional administrations, or associations of municipalities (mancomunidades and comarcas)—must sponsor a project, negotiate land tenure with ADIF, and assume long-term operational and maintenance responsibilities once civil engineering works are complete.

The Santander–Mediterráneo corridor was identified as the premier long-distance greenway project in Spain. Once fully developed, it would form a continuous corridor exceeding 500 kilometres, running through Cantabria, Castile and León, Aragon, and connecting into the Valencian Community via the adjacent Vía Verde de Ojos Negros.

Section	Provinces Traversed	Approx. Length	Development Status	Primary Managing/Promoting Body
Trasmiera / Pas (Cantabria)	Cantabria	45 km	Partially conditioned (open in sections)	Government of Cantabria
Las Merindades (Burgos North)	Burgos	60 km	Conditioned and open	Diputación Provincial de Burgos / MAPA
La Bureba / Burgos Capital	Burgos	45 km	Conditioned and open	Diputación Provincial de Burgos / MAPA
Burgos South / Campiña Soriana	Burgos / Soria	65 km	Conditioned and open	Diputación de Burgos / Diputación de Soria
Soria Central (San Leonardo–Soria)	Soria	56 km	Conditioned and open	Diputación Provincial de Soria / MAPA
Campo de Gómara (Soria–Ciria)	Soria	43 km	Conditioned and open	Diputación Provincial de Soria / MAPA
Ribota Valley (Border–Calatayud)	Zaragoza	43 km	Unconditioned (missing gap)	ADIF ownership; unassigned
Vega del Jiloca (Calatayud–Daroca)	Zaragoza	45 km	Conditioned and open	Comarca de Calatayud / Comarca de Daroca
Jiloca Sur (Daroca–Caminreal)	Zaragoza / Teruel	40 km	Conditioned and open	Comarca de Daroca / Comarca del Jiloca

Geographical Alignment of the Missing Section

The unconditioned section spans 43 kilometres entirely within the administrative territory of the province of Zaragoza, belonging to the autonomous community of Aragon and managed locally under the Comarca de la Comunidad de Calatayud. The railway alignment follows the natural geographic descent from the Castilian plateau down through the Ribota River valley to the Jalón depression.

The section begins at the regional border between Ciria (Soria) and Torrelapaja (Zaragoza) at an elevation of approximately 1,000 metres above sea level. From this high point, the rail line descends continuously toward Calatayud, which sits at an elevation of roughly 534 metres, maintaining an engineered railway gradient that rarely exceeds 1.5 to 1.6 percent (15 to 16 thousandths).

Geographically, the corridor is divided into three distinct segments:

• The Upper Ribota Plateau (Border to Malanquilla): The line enters Aragon just west of Torrelapaja, cutting through cold, windswept limestone and marl plateaus. It runs near the headwaters of the Manubles and Ribota river systems, bordering the Sierra de la Virgen to the northeast.
• The Middle Ribota Valley (Clarés de Ribota to Cervera de la Cañada): The railway enters the valley of the Ribota River, a seasonal tributary of the Jalón. Here, the valley floor broadens slightly, flanked by arid, eroded hills of red clay, sandstone, and limestone. The surrounding agricultural land is cultivated with rainfed grains, almond orchards, vineyards (belonging to the Denominación de Origen Calatayud), and traditional fruit orchards.
• The Lower Valley and Calatayud Approach (Torralba de Ribota to Calatayud): The corridor parallels the modern N-234 road, navigating a series of deep earth cuttings (trincheras) and sweeping embankments (terraplenes). Approaching Calatayud, the railway cuts across irrigated bottomlands before reaching the former station complex of Calatayud-Ribota and terminating near the main Madrid–Barcelona railway corridor.

Station or Stop	Railway Kilometre (approx.)	Elevation (m)	Municipality	Present Physical Condition
Boundary / Border	km 43.0	1,005	Torrelapaja / Ciria border	Abrupt transition from compacted gravel to rough ballast
Torrelapaja	km 40.2	989	Torrelapaja	Passenger building abandoned, roof partially intact; overgrown yard
Malanquilla (Halt)	km 34.8	990	Malanquilla	Building derelict; trackbed buried under weeds and ballast
Clarés de Ribota (Halt)	km 27.1	760	Clarés de Ribota	Small masonry shelter deteriorated; earthworks overgrown
Villarroya de la Sierra	km 20.4	735	Villarroya de la Sierra	Multi-track yard intact; main passenger station and warehouse abandoned
Cervera de la Cañada	km 13.9	703	Cervera de la Cañada	Station building and water reservoir derelict; metal bridge decks unplanked
Torralba de Ribota	km 8.2	625	Torralba de Ribota	Station intact but sealed/vandalised; ballast bed intact
Calatayud-Ribota	km 1.5	540	Calatayud	Extensive industrial yard; rails removed; connection to AVE line severed

Current Physical State and Traversability

The unconditioned status of the Torrelapaja–Calatayud section means that it remains an unmanaged brownfield transport corridor. It presents substantial navigational and physical difficulties for all forms of non-motorised transit.

The ground surface consists largely of the original basalt and limestone railway ballast. Because the track was pulled without subsequent levelling, the bed features two deep parallel depressions left by the extraction of the sleepers, interspersed with mounds of loose, coarse, angular crushed rock (ranging from 30 to 60 mm in size). Traversing this surface on a standard touring, road, or gravel bicycle is virtually impossible; it causes severe tyre slippage, instability, and a high risk of sidewall punctures. Only mountain bicycles equipped with high-volume, low-pressure tyres can negotiate portions of the line, and even then, riders face sustained physical fatigue.

Natural erosion and invasive vegetation have further degraded the corridor. Without vegetation control, extensive sections—particularly in cuttings where moisture collects—have been colonised by dense thickets of wild rose, brambles, gorse, thistles, poplars, and blackthorn. In several locations, water run-off from torrential storms (common to the semi-arid climate of the Iberian System) has washed out embankments and filled drainage ditches with silt, causing deep gullies across the trackbed.

Civil engineering structures present severe safety hazards:

• Bridges and Viaducts: The metal girder bridges and stone-and-concrete viaducts over the Ribota River and local ravines have had their track assemblies removed. The steel superstructure remains, but the gaps between structural transverse beams are exposed. There is no timber decking, concrete slabs, or safety railings. Crossing these structures requires walking along narrow, exposed steel flanges above drops of 5 to 15 metres, which is dangerous for hikers and impossible for horses or loaded bicycles.
• Level Crossings: Where the old railway intersects paved regional roads, agricultural tracks, or the national highway (N-234), the original grade crossings have either been paved over with asphalt or cut away by road-widening works. This creates steep, unmarked, and blind drops onto active motorways with high-speed vehicular traffic.
• Station Heritage: The station buildings at Torrelapaja, Villarroya de la Sierra, Cervera de la Cañada, and Torralba de Ribota are unmaintained. Several have suffered roof collapses, fallen floorboards, missing lintels, graffiti, and structural cracking. Goods warehouses and outbuildings are occasionally used informally by local agriculturalists for storage or livestock shelter, but most are deteriorating under exposure to winter frosts and summer heat.

Cyclists undertaking the trans-Iberian route across Spain must leave the railway corridor at Ciria or Torrelapaja and divert onto the N-234 road or the secondary A-1502 road. While these roads offer a paved alternative, the N-234 is a primary national corridor carrying heavy commercial truck traffic, featuring narrow shoulders and high design speeds, presenting clear risks to non-motorised users.

Causes of the Inter-Autonomous Boundary Impasse

The failure to complete the 43 kilometres between Torrelapaja and Calatayud is rooted in the administrative decentralisation of Spain and the differing political priorities of regional institutions.

Decentralised Administration and Border Friction

Spain is organised into seventeen autonomous communities, each possessing exclusive competence over regional spatial planning, environmental protection, regional tourism, and cultural heritage. Provincial councils (diputaciones) and comarcal bodies manage local municipal services and rural infrastructure within their specific territorial borders.

The border dividing Castile and León (Soria province) from Aragon (Zaragoza province) represents a rigid administrative boundary. The Diputación Provincial de Soria viewed the conversion of the Santander–Mediterráneo line as a flagship territorial cohesion initiative. Soria, one of the most demographically depleted provinces in the European Union, invested local matching funds, worked closely with MAPA, and systematically completed the conversion from San Leonardo de Yagüe in the west through Soria capital, pushing the works across the agricultural expanse of the Campo de Gómara directly to the Aragonese border at Ciria.

Upon reaching the border at Torrelapaja, the project crossed into an entirely different administrative jurisdiction. The Government of Aragon (Diputación General de Aragón), the Diputación Provincial de Zaragoza (DPZ), and the Comarca de la Comunidad de Calatayud operate under independent budgetary priorities and infrastructure schedules. The Soria council had no jurisdiction or legal mandate to allocate funds across the border, bringing the greenway to an immediate halt at the provincial boundary line.

Territorial Prioritisation within Aragon

The Aragonese regional administration and the Comarca de la Comunidad de Calatayud did not oppose the conversion of the Santander–Mediterráneo line; instead, they prioritised a different portion of the corridor. Calatayud is situated at a strategic railway junction where the line to Soria branched north-west, while the line to Daroca, Caminreal, and Teruel extended south-east.

Aragonese authorities concentrated their planning, funding applications, and operational agreements on the southern corridor: the Vía Verde de la Vega del Jiloca and its continuation through Daroca to Caminreal. This southern link was prioritised for specific strategic reasons:

1. Connection to Ojos Negros: Caminreal serves as the historic connection point to the Vía Verde de Ojos Negros, the longest existing greenway in Spain (running over 160 kilometres from the mines of Ojos Negros through Teruel to Sagunto). By conditioning the Calatayud–Daroca–Caminreal railway corridor, Aragon linked Calatayud directly into an established, heavily promoted tourism network extending to the Mediterranean coast.
2. Regional Demographics: The Jiloca valley contains larger population centres, including Daroca, and experienced greater local advocacy from comarcal federations demanding economic stimulus along that specific corridor.
3. Budgetary Constraints: Under MAPA's Caminos Naturales programme, the ministry finances the execution of the works, but the local managing entity must prepare the initial technical projects, obtain environmental permits, secure the lease agreement with ADIF, and formally commit to all recurring maintenance costs. The Comarca de Calatayud lacked the capital and technical administrative staff to prepare and maintain two major railway corridors simultaneously. Consequently, the Ribota valley line was deferred.

Institutional Complexity with ADIF

The underlying real estate of the railway corridor remains under the ownership of ADIF. Under Spanish law, disused railway lands cannot simply be appropriated by local towns or cycling clubs. To convert a line into a greenway, a formal administrative lease or right-of-use contract (arrendamiento de activos ferroviarios en desuso) must be executed between ADIF and a recognised public entity, typically for a period of 20 to 50 years.

The small rural municipalities along the Ribota valley—such as Torrelapaja, Malanquilla, and Cervera de la Cañada—have limited administrative capacity. These village councils lack municipal engineers, legal counsel, or discretionary budgets to negotiate long-term property contracts with a national state enterprise. ADIF charges an annual lease fee (often nominal, but paired with substantial legal liabilities for maintenance, public safety, and insurance). Without the leadership of a higher-tier entity, such as the Aragonese regional government or the DPZ, the municipalities were individually unable to advance the administrative dossier.

Socio-Economic Context: "España Vaciada" and the Ribota Valley

The territory crossed by the missing section lies within what Spanish demographers and social scientists refer to as the España Vaciada (Empty or Hollowed-out Spain). This region of southern Soria and western Zaragoza is characterised by severe depopulation, extreme ageing, and low population density, often falling below 5 inhabitants per square kilometre—comparable to the Arctic regions of Scandinavia.

Municipality	Population (approx. 2023)	Area (km²)	Density (pop/km²)	Dominant Economic Activity
Torrelapaja	35	15.7	2.2	Dryland agriculture (cereal grains)
Malanquilla	90	36.6	2.5	Grain, sheep farming, heritage tourism
Clarés de Ribota	25	18.7	1.3	Agriculture, fruit farming
Villarroya de la Sierra	435	91.6	4.7	Viticulture, fruit production, services
Cervera de la Cañada	264	29.2	9.0	Vineyards, fruit orchards
Torralba de Ribota	168	32.5	5.2	Agriculture, cultural tourism (Mudejar)

The closure of the railway in 1985 accelerated the economic and demographic decline of these settlements. Local schools closed, small businesses ceased trading, and working-age populations moved to Zaragoza, Madrid, or Barcelona. In this context, greenways and cycling tourism (cicloturismo) are viewed by regional advocates not merely as leisure amenities, but as sustainable economic regeneration tools.

Evidence from established sections of the Santander–Mediterráneo greenway in Burgos and Soria demonstrates that long-distance cycle tourists generate measurable demand for rural hotels, hostels, guesthouses, restaurants, bakeries, and local bicycle repair enterprises. The Ribota valley possesses cultural assets, including notable Mudéjar architecture (such as the fortified church of San Félix in Torralba de Ribota, designated as part of a UNESCO World Heritage site), fortified medieval churches, local wineries, and scenic landscapes. However, the lack of a safe, off-road connection prevents these small communities from capturing the cycle-tourist traffic that flows across the Iberian Peninsula.

Advocacy and Conversion Initiatives

Over the past two decades, local governments and civil society have mounted campaigns to resolve the Torrelapaja–Calatayud bottleneck. A coalition of local mayors from the Ribota and Manubles valleys has met with representatives from the Government of Aragon, the Diputación de Zaragoza, and the central Ministry of Agriculture to demand parity with the work done in Castile and León.

Cycling advocacy organisations, such as the national federation ConBici, along with regional railway preservation societies (including the Asociación Zaragozana de Amigos del Ferrocarril y Tranvías, AZAFT), have conducted promotional rides, rallies, and media events. These initiatives aim to highlight the contrast between Soria's fully surfaced path, which ends in an overgrown gravel embankment at the Aragonese border, and the unfinished track ahead.

In response to these demands, the Ministry of Agriculture, Fisheries and Food produced technical preliminary drafts (anteproyectos) and feasibility studies assessing the corridor. The engineering proposals break the works down into manageable phases:

• Phase I: Torrelapaja to Villarroya de la Sierra (approx. 23 km): Addressing the high-plateau section, including clearing the ballast, laying a consolidated gravel surface (zahorra compactada), clearing culverts, and securing the station yards of Torrelapaja and Malanquilla.
• Phase II: Villarroya de la Sierra to Calatayud (approx. 20 km): Involving complex structural engineering, specifically the timber decking and safety railing installation across the metal girder viaducts over the Ribota River, road crossings along the N-234, and integrating the trail into the urban network of Calatayud.

Motions have been passed in the Aragonese regional parliament (Las Cortes de Aragón) urging the regional executive to formalise the land agreement with ADIF and submit the final construction project (proyecto constructivo) to MAPA. While central authorities have periodically included line items in draft budgets for environmental studies along the route, the tendering of physical construction works has suffered repeated delays due to shifting ministerial budget allocations, fiscal austerity, and competing public works priorities elsewhere in the national greenway network.

Technical Requirements for Completion

Converting the remaining 43 kilometres of abandoned railway into a standard Vía Verde / Camino Natural requires resolving specific civil engineering and infrastructure challenges inherent to neglected rail beds:

Surface Treatment and Ballast Management

The primary technical challenge is the presence of thousands of tonnes of residual track ballast. Complete removal and transport of the ballast off-site is cost-prohibitive and environmentally unsound. Standard practice developed by MAPA on other Santander–Mediterráneo sections involves:

1. Grading, spreading, and heavily compacting the existing ballast bed to form a stable structural sub-base.
2. Applying a geotextile membrane to prevent the upward migration of fine soils and inhibit weed growth.
3. Laying an intermediate layer of graded natural aggregate (zahorra artificial) compacted to high density.
4. Finishing with a multi-use surface, typically a top layer of compacted limestone dust or crushed aggregate bound with ecological resin. In steep cuts or flood-prone sections, an asphalt concrete layer or porous cement pavement is required to prevent water erosion.

Structural Rehabilitation of Viaducts

The metal viaducts along the Ribota valley require structural safety certifications. Although the primary steel lattice girders and masonry abutments remain structurally sound, decades of rust and lack of paint maintenance necessitate sandblasting, anti-corrosion chemical treatments, and structural testing. The installation of non-slip treated timber or composite boardwalk decks, complete with certified 1.2-metre-high pedestrian fall-protection railings, is legally mandated before these structures can be opened for public access.

Drainage and Slope Stabilisation

The Ribota valley is subject to seasonal Mediterranean flash-flood dynamics (ramblas). The line's historical stone and masonry drainage culverts (tajeas and alcantarillas) have suffered from siltation and blockage by vegetation. Comprehensive clearance, repairing cracked stone headwalls, and re-excavating longitudinal side ditches are essential to prevent heavy seasonal run-off from undermining the trackbed. In deep limestone cuttings, dynamic rockfall protection netting and catchment barriers are required to protect trail users from falling stones dislodged by freeze-thaw cycles.

Intermodal Integration at Calatayud

The southern terminus of this missing section holds exceptional strategic value for Spain's national transport network. Calatayud is an operational stop on the Madrid–Zaragoza–Barcelona high-speed rail line (AVE). The Calatayud railway station also accommodates regional trains (Media Distancia) linking Madrid, Soria, and Zaragoza.

Completing the trail directly into the Calatayud transport hub would create an intermodal gateway for cycle tourism in southern Europe. Rail passengers carrying bicycles can depart high-speed trains from Madrid-Puerta de Atocha or Barcelona-Sants and access the greenway directly at Calatayud. From this point, cyclists could ride north to Soria and Santander, or south through Daroca, Teruel, and Valencia to the Mediterranean coast, without needing private motor transport or navigating mixed vehicular traffic.

Significance within the European and Trans-Iberian Networks

The resolution of the Torrelapaja–Calatayud bottleneck is the single requirement needed to establish an uninterrupted non-motorised trans-Iberian route across Spain. Combined with the adjoining segments already completed or under construction, the route would form an off-road corridor of over 750 kilometres connecting the Atlantic to the Mediterranean:

• Santander to Cidad-Dosante: Utilizing the Cantabrian greenways and the Las Merindades sections (Cantabria/Burgos).
• Cidad-Dosante to Soria: Across northern Burgos and western Soria (open and fully functional).
• Soria to Ciria: The eastern Soria section (open and fully functional).
• Ciria/Torrelapaja to Calatayud: The 43-kilometre missing section (Ribota Valley).
• Calatayud to Caminreal: The Vega del Jiloca and Daroca sections (open and fully functional).
• Caminreal to Sagunto/Valencia: The Vía Verde de Ojos Negros (open and fully functional across Teruel, Castellón, and Valencia).

While the route is not currently integrated into the official EuroVelo network (which includes routes like EuroVelo 1 down the Silver Route and EuroVelo 3 across the Camino de Santiago), international cycling advocacy bodies, such as the European Cyclists' Federation (ECF), recognise this corridor as one of the most promising long-distance nature trails in Europe. Its continuous low gradient, isolation from motor vehicles, and passage through diverse historical regions give it considerable potential for non-motorised active travel.

Until regional and national authorities tender the engineering contracts and complete the civil works through the Ribota valley, the boundary between Castile and León and Aragon remains an administrative barrier, dividing a multi-million-euro national infrastructure project into two disconnected halves.

See also

• Ferrocarril Santander-Mediterráneo
• Vía Verde de Ojos Negros
• Vías Verdes
• Caminos Naturales de España
• Comarca de la Comunidad de Calatayud
• Rail trail
• Administrador de Infraestructuras Ferroviarias
• Transport in Spain