Karrantza has a rich natural heritage on the surface. Under the ground, however, it is a brand-new world whose unique characteristics are all illustrated in the Pozalagua Cave.

Pozalagua was found by chance, as it does not open to the exterior. Dolomite exploitation activity in a nearby quarry was carried out using dynamite. In 1957, one such explosions revealed a veritable geological treasure. Unfortunately, the blast destroyed many stalactites and stalagmites, but most of the cave, which formed in about 50 million years, remained intact.

The cave has been carefully equipped for visitors to come in by way of a metal walkway flanked by stalactites, curtains and stalagmite columns.

The central chamber has a 20m dome supported by majestic limestone and dolostone columns, coloured by iron oxide. Everything here has grown from subsequent drops falling and forming a Baroque decoration of fragile and twisting eccentric stalactites.

The causes of such eccentric formations are unknown. The walls of the cave show peculiar images like the face of a witch, a sirloin steak or a willow. Visitors are not allowed to touch anything inside the cave.

Beyond Pozalagua

A few metres away from the cave there stands Torca del Carlista, the largest sinkhole in Europe and the second largest in the world. It is only open to experienced cavers.

There must have been a central lagoon where the roof looked at itself as in a mirror, but the last explosion in the quarry caused leaks that let the water out. At the far end of the cave is a viewpoint to soak up the hidden beauty of Pozalagua.

A visit to the cave is great for families travelling with kids, since the little ones will have fun trying to discover new images between the stalactites. Also, children love Karpin Fauna, an educational park and wildlife recovery centre only 10km from Pozalagua.

Adjoining the cave, on the site of the old quarry, there is auditorium with a seating area. In mid-July, the auditorium plays host to an open-air music festival starring Basque musicians and singers.

How to get there

Long distances between towns in the Karrantza Valley, the widest in Bizkaia, are commonplace. There are bus lines that carry passengers to some of the neighbourhoods but not to Ranero, where the cave lies.

  • Train

    The FEVE line runs from Bilbao to Karrantza in an hour. Get off at Ambasaguas (La Estación). Take a taxi at the train station or head to the cave on foot (two-hour walk).

  • Bus

    Two bus lines depart from Termibus: Bilbao-Zalla-Karrantza and Bilbao-Zalla-Lanestosa. You will need to transfer at Zalla to reach your destination.

  • Car

    You can take either the coastal road or the one that runs across the interior. From Bilbao, take highway A-8 (Bilbao-Santander), exit at Balmaseda by way of Corredor del Cadagua (road BI-636), which passes through Alonsotegi, Zaramillo and Zalla to get to Malabrigo. Then get onto road BI-630 and continue past Traslaviña to reach the mountain pass of La Escrita, which leads to Karrantza. If you choose to take the coastal route, get into highway A-8 (Bilbao-Santander), exit at Colindres, then take road N-629 in the direction of Burgos-Logroño. Pass through Limpias, Ampuero and Rasines. On arriving at the narrow pass of Gibaja, take road BI-630 toward Balmaseda-Vitoria. You will get into the valley by the gorge of Karrantza.


Where to eat

Very close to the cave you will find a picnic area. The views of the valley are majestic. If you prefer to sit at a restaurant or bar, there are a lot of them in the nearby towns. They serve the best of our traditional recipes. Our recommendations: bean stew or lamb. Prices are accessible.

You can bring home an edible souvenir like Carranzana sheep milk cheese, Idiazabal cheese, organic cheese or yoghurt, cold meats (black pudding, bacon, chorizo), or artisan pastries and desserts.


Where to sleep

Lodges and country homes are the best choice to stay in the Karrantza Valley, surrounded by a rather unknown yet fabulous natural setting in Bizkaia.

For an extra treat, try the healing waters from the hot springs at El Molinar, in Karrantza. The spring water, whose temperature ranges between 29 and 33 ºC, has been used since the nineteenth century. They say it works wonders for rheumatism and arthritis, among other musculoskeletal conditions.

  • The Pozalagua Cave is 52km away from Bilbao, in Peñas de Ranero, Armañón Nature Park. Unique for its rare stalactites that take on peculiar shapes, the cave is ideal to visit if you are travelling with kids and is fully accessible.

    Pozalagua Cave
    Peñas de Ranero (A 2 km del barrio de Ranero)
    48891 Karrantza, Bizkaia
    Telephone: 649 811 673 (Cave) / 946 806 928 (Karrantza Valley Tourist Office)
    Email address: info@karrantza.com

    • Timetable

      From 1 April to 15 October: 11:00am-8:00pm (last admission 7:00pm)
      From 16 October to 31 March: 11:00am-6:00pm (last admission 5:00pm)
      Closed on Monday (except holidays), 1 and 6 January, 18 September, and 24, 25 and 31 December

    • Price

      Adults (over 16): €7
      Children (8-16): €4
      Seniors: €4
      Students (with proof of student status): €4
      Adult groups: €4
      School groups: €3
      Spelunking association members: Free

    • Location

      Karrantza Valley 

  • Bring comfortable shoes and warm clothes. The temperatures inside the cave remain a constant 13 ºC year round. Guided tours last 50 minutes. Taking photographs and touching the stalactites are not allowed.