Running from Zumaia west to Deba and Mutriku, this narrow coastal strip encompasses meadows, forests, caves and, most importantly, 13km of dramatic cliffs. The layered formations of flysch deposits show 60 million years of the earth's history, from roughly 50 million to 110 million years ago.
There are various paths you can take, from the 1.5km Algorri route that takes you along the cliffs outside of Zumaia, to the 10.9km Talaia trail, going from Zumaia all the way to Itxaspe. Guided walking tours and boat trips are on offer. Book online or through the tourist office well in advance.