Following the route of the E9 – European Coastal Path, which coincides in Bizkaia with the coastal stretch of the GR 123 – Tour of Bizkaia path, we can get up close to many of Uribe’s geological treasures.
Flysch Route of Bizkaia
Along Bizkaia flysch route, as you pass through Gorliz, you will find 3 Places of Geological Interest (LIG) marked with 3 interpretive panels.
Fossil dunes of Astondo
The Astondo dunes are part of a chain of quaternary coastal dunes, fossilised around 6000 years ago and colonised by vegetation. We can see layers of sediment in them, resting on top of the Late Cretaceous flysch.
- Upper layer: fine sand with vegetation.
- Intermediate layer: cemented biogenic sands, with bivalves, gastropods and foraminiferas.
- Lower layer: sandy shale with remains of gastropods and foraminiferas.
A rocky promontory formed more than 120 million years ago from the remains of a coral reef and molluscs.
It represents a transition point between the black flysch (of the Lower Cretaceous period) and the calcareous flysch (of the Late Cretaceous period).
In the 18th century, a fort was built in this unique location, with the aim of preventing a possible attack by English ships in the Gulf of Biscay. Over the years, it fell into disuse and slowly deteriorated.
Today it is an exceptional viewpoint towards to coast of Uribe.
Ensemble of Cabo Billao
The materials that make up Cabo Billao, a Place of Geological Interest, were formed in the Cretaceous period, 110-90 million years ago, in a period of intense tectonic activity in the Basque-Cantabrian Basin.
Later collisions and the action of the waves moulded this part of the coast until it reached its current shape.
The Lighthouse, was built in 1990 in this place and is believed to be the tallest lighthouse on the Cantabrian coast, being on Cantabrian coast, being on top of a 165m-high cliff.
The action of the sea on the coast has been responsible for sculpting the cliffs and creating islets such as Cabo Billao, which provide shelter for many sea birds. Living on them are Mediterranean species, such as Olea europaea or Lavatera arborea, which reached here thanks to migratory birds.