Pictures by Albontza Irijalba.

The coastal strip located in the western part of Gipuzkoa’s coast, between the mouths of the rivers Deba (in the village of Deba) and Urola (in Zumaia), covers around 8 kilometres of cliffs, being a surprise for everybody visiting this area. This strip includes elements of geological and geomorphological value with an internationally recognised prestige, as well as the richest and most complex marine ecosystem in the entire Basque coast. All these natural values have had an excellent conservation due to the difficult access to the area, so it has become one of the most interesting and unknown natural treasures of our country.

From a landscape point of view, the environment presents three welldistinguished units: the inner lands, the cliffs and the extensive tidal platform. In this section of the coast, the Cantabrian Sea’s strength has eroded the smooth clayey materials of the flysch, sculpting amazing cliffs that leave one of the most extensive tidal zones in Europe on their way backwards. This horizontal platform consists of an endless sequence of sharp and capricious rock layers shaping a real visual caprice. The dynamic of cliffs and all the related geomorphological features, such as hanging valleys, small coves, big fallen blocks or differential erosion present here perfect examples.

The layered materials of the flysch represent a first-rate geological sanctuary at an international level. Zumaia’s flysch is one of the most spectacular and beststudied outcrops in the world, since it gathered all the climatic, biological and geological events of the Earth for fifty million years. At present, this layers are upright, turning this outcrop into a big Earth History book where we can discover some of the best kept secrets of our planet’s evolution: the disappearance of the dinosaurs 65 million years ago (K/T boundary - Cretaceous-Tertiary-), the climatic cycles, the last great climatic change warming (P/E boundaryPaleocene/Eocene-), the uplift of the Pyrenees, etc.  The Zumaia paleocene has recently been chosen by the international geological community in order to host the estratotipos Danian-Selandian and Selandian-Thanetian stratotypes dating from 60.8 y 58.7 My. respectively. This way, the amazing Itzurun Beach becomes part of the international geological calendar, receiving the official recognition it is worth.  A new world to discover in an exciting travel through time.

In addition to the aforementioned geomorphological and geological interest, the tidal platform houses the richest and most complex ecosystem of our coast. Its pools are real natural aquariums with countless species of plankton communities, benthic species, algae, fishes, crustaceans, cnidarians, molluscs and echinoderms. A real explosion of biodiversity, colours and living shapes.