El Pozo Azul

El Pozo Azul is an expert-level cave diving site in Cantabria, northern Spain, featuring one of Europe's longest explored underwater cave systems. The entrance pool glows an ethereal blue color, giving the site its name. The cave system extends for over 13 kilometers of explored passages through limestone formations. Only certified cave divers with extensive experience should attempt this site. The crystal-clear water and dramatic cave formations make El Pozo Azul one of the most significant cave diving sites in Europe.