Túnel de San Adrian

Tunnel of San Adrian

Useful Information

Location: Mount Aizkorri Near Oñati, Aránzazu valley. From Motorway A-8, exit Maltzaga, follow Motorway AP-1 to Mondragón, then GI-627 to San Prudencio and GI-2630 to
Open: No restrictions.
Fee: free.
Classification: SubterraneaCave Church, SpeleologyKarst cave.
Light: bring torch
Guided tours:
Address: Oficina de Turismo de Oñati, Plaz de los Fueros, 20560 Oñati, Tel: +34-943-783453, Fax: +34-943-783069. E-mail: contact
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
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Túnel de San Adrian is a natural cave which is actually used as a tunnel. The through cave connects Gipuzkoa and Álava-araba. The Romans built a road leading up to the cave, which later became the Medieval inland road to Santiago. Today it is used by mountaineers, as the trail to mount Aizkorri runs through the cave. The bigger entrance shows the remains of buildings.