Geoparque de la Costa Vasca en Mutriku Nature · Mutriku, Debabarrena / Bajo Deba, Gipuzkoa Mutriku's coastline forms part of the Basque Coast UNESCO Global Geopark, declared in 2015, with flysch formations and a jagged coast of great geological value. Geoparque declarado en 2015 Photo: Txo (CC0) What to see and do in Mutriku