Arrikrutz The Oñati Caves

Tourist project for the appreciation of the natural and cultural assets of the Oñati-Arrikrutz karst in Oñati (Gipuzkoa)

The Oñati town council plans to set up a unique nature tourism project based on the OÑATI-ARRIKRUTZ karst, located closed to the Aranzazu Sanctuary. The project, based on the directives established by the town's recently completed Strategic Plan, will generate a product to pursue an appreciation of Oñati's natural, social and cultural environment. It also aims to promote sustained development in the local and regional context.

Arrikrutz, Oñati, Euskadi

The countryside around Oñati is very interesting and beautiful. Among other things, close to the Arantzazu Sanctuary and blow the Aizkorri massif, the town has a very attractive, imposing karst (scenery typical of a limestone region), with a very extensive and complex system of potholes.

Arrikrutz was one of the first sites to be explored in potholing, archaeological and palaeontological terms in the Basque Country. The initial work led to the discovery of palaeontological remains such as:

Arrikrutz, Oñati, Euskadi

  • A complete skeleton of a cave lion, the first find of this type in Spain.
  • Partial panther skeletons and craniums.
  • An impressive bear site.

In the field of mythology, hundreds of years ago, the inhabitants of Oñati, the Alto Deba valley and the neighbouring province of Alava used to come to the Sandaili cave in search of rain for their land.

Sterile women also used to bathe in the waters of Sandaili in search of fertility, performing rites dating back thousands of years, from the age of the gentiles.

This is why the Town council of Oñati has decided to improve and complete what the town offers in terms of nature tourism, by preparing the Oñati-Arrikrutz cave for visits.

Arrikrutz, Oñati, Euskadi

After four years of work, the Arrikrutz cave have been opened to the public on the 8th of June in 2007.

A number of studies have therefore been carried out to obtain detailed information about the physical, environmental and cultural aspects of the cave.

As part of the project, a highly advanced computer system will be developed to guide the visits and provide information about the various historic, ethnographic, geological and mineral features to be found in the cave.

During the 60 minutes that it will take to walk through the cave, the system will cover the following subjects in an attractive, educational way:

  • Water and hydrology as the sculptors of the cave.
  • The Arrikrutz cave as just part of the more than 14 km of the vast, complex Gesaltza-Arrikrutz sinkhole system.
  • The geological formation of the cave and an appreciation of its beauty, which includes a subterranean river and a gallery full of enormous stalactites.
  • The origin of the mineral universe.
  • The archaeological and palaeontological finds in Arrikrutz.
  • The mythology around Sandili.
  • The importance of Arrikrutz in the history of potholing.


From Tuesday to Sunday (closed on Mondays)

March-May and October 10:00-14:00/15:00-18:00

June-September 10:00-14:00/15:00-19:00

November-February 10:00-14:00/ 15:00-17:00

Festivals, Easter, and Vacations, it will be opened in June-September schedule


Adults 8 euros

Retired people and Children ( 5-10 years old) 6 euros (0-4 years old, free entrance accompanied by an adult)

Groups ( for groups of more than 15 people) 6 euros

Telephone: (+34)943-082000 |

Photos from the Aloña Mendi potholing group


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