Armañón Natural Park

Armañón Natural Park is the ninth natural park declared in the Basque Country, spread across the municipalities of Karrantza and Turtzioz in the westernmost part of Biscay. It covers close to 3,000 hectares of mountainous terrain that forms one of the defining massifs of the Encartaciones region's landscape. The highest point is the Armañón peak itself, rising to 854 metres, flanked by other notable summits such as Ranero (737 m), Surbias (638 m) and Los Jorrios (837 m).

What defines the landscape of the park?

The park's terrain is shaped above all by limestone formations, which over millennia have carved out an extensive underground world. More than 200 caves have been identified within its boundaries, the most famous being the Pozalagua Cave, home to the largest known concentration of eccentric stalactites in the world — mineral formations that grow in twisted, irregular directions rather than following gravity in a straight line. This geological rarity draws speleology enthusiasts from across Spain and beyond.

Above ground, the park is covered by dense oak woodlands and evergreen groves, interspersed with open countryside that has been shaped for generations by traditional livestock grazing. This mix of habitats — underground caves, rocky ridgelines and pastoral meadows — gives the park an unusually varied character for its relatively compact size.

What can visitors do here?

Armañón is above all a destination for outdoor activities. Its network of trails supports hiking of varying difficulty, from gentle walks through oak forest to more demanding climbs toward the Armañón summit, which offers views over the surrounding mountain ranges and the Carranza valley. The terrain also lends itself to horseback riding and mountain biking, giving visitors different ways to experience the park depending on their pace and interests.

Birdwatchers will find the park's rocky cliffs and open spaces to be natural habitat for numerous species, making it a worthwhile stop for ornithological outings. Those drawn to geology and underground landscapes can also explore its caving opportunities, though visiting the Pozalagua Cave itself typically requires organised access given the fragility of its formations.

Where exactly is the park located?

Armañón sits at the western edge of Biscay, between the towns of Karrantza and Turtzioz, in the historic Encartaciones region. This is a border area adjoining Cantabria, giving it a somewhat different landscape character compared to the more familiar coastal parts of the Basque Country.

Frequently asked questions

How large is the park? Sources cite figures ranging from roughly 2,996 to 3,519 hectares, depending on the boundaries considered for the protected area.

What is the highest peak? The Armañón summit, at 854 metres above sea level, which gives the park its name.

What is the park's main geological attraction? The Pozalagua Cave, known for the world's largest concentration of eccentric stalactites.

What activities are available? Hiking, horseback riding, mountain biking, birdwatching and speleology.

Which municipalities does the park belong to? Mainly Karrantza and Turtzioz, in the province of Biscay.