Starting point Pozalagua Cave

Our day plan takes us to Karrantza, the westernmost valley in the Enkarterri region. We start the day by visiting the Pozalagua Cave.

The cave is situated in the heart of the Armañón Natural Park. This cathedral-like underground world is home to the highest concentration of eccentric stalactites in the world. These peculiar formations grow randomly in all directions, defying gravity and forming a spellbinding mosaic. The cave was discovered by chance following an explosion in a nearby quarry that opened up a hole in the mountain. On the other side, a dazzling underground universe emerged. The visit takes you past stalactites, stalagmites and flows, and culminates with a viewpoint that presents the cavern in all of its splendour.

Facing the cave is the Parketxea or Armañón Natural Park Information Centre, which presents all of its secrets through a permanent exhibition and viewpoint with spectacular views.

Once the visit is over, you can recharge your batteries at the bar-restaurant next to the cave or head to the centre of the valley where there’s a wide and varied range of cuisine on offer. In Karrantza you can opt to visit BBK Karpin Fauna, a refuge for more than 55 different species of animals that can no longer live in the wild, or immerse yourself in part of industrial history by visiting the Dolomitas Museum.

Lastly, around 15 km from the Karrantza Valley, is Lanestosa, a charming town where time seems to have stood still since its foundation in the 13th century. The municipality, the smallest in Bizkaia, is perfect for delving into and walking around its historic centre of cobbled alleyways, medieval bridges and traditional houses with continuous balconies. The surroundings of the town are encircled by great mountain massifs full of hiking routes and perfect viewpoints.

Starting point Paseo de Aixerrota

The Flysch of Bizkaia is a geological marvel that stretches from Aixerrota (Getxo) along the entire coast of the Uribe region to Bakio. This spectacular landscape of cliffs and sedimentary strata tells stories of millions of years, showing layers formed by the accumulation of materials submerged at the bottom of the sea.

The Flysch of Bizkaia offers a variety of walking routes. In this case, one of the most complete routes, which will lead you to discover most of the geological points of interest of the Bizkaia Flysch, is the so-called Cliffs Route which links Getxo with the fishing quarter of Armintza in Lemoiz. The route covers 29 km in total and can be started at any point, but we recommend you do it from the beginning, from Aixerrota. One of the highlights of the route is the Golden Spike located on the Gorrondatxe-Aizkorri Beach, an accolade awarded by the International Union of Geological Sciences for its international geological importance.

The first part of the Cliffs Route is ideal for discovering the beaches of Getxo, Sopela and Barrika. It then continues through the medieval historic centre of the town of Plentzia, where you can stop to savour its cuisine at the foot of the Plentzia Estuary, and it continues through Gorliz with its magnificent beach and lighthouse, before heading into the final straight and ending at the Armintza fishing port. Beyond the breakwater you’ll come across the black Flysch, a fascinating geological formation.

Those who aren’t able to do the different walking routes can park in designated areas and head to any of the 14 geological points of interest, or join the guided tours scheduled throughout the year. The K–T boundary in Sopela is accessible for people with reduced mobility right up to the geological feature itself, a site of great global importance.