In the gulf of Ártabro, the Dexo-Serantes coast stretches from the port of Lorbé to the Mera lighthouse, forming an extraordinary protected coastal ecosystem that has been declared a Natural Monument.

A spectacular coastal landscape of cliffs and grottoes between the Ares, Betanzos and A Coruña estuaries is the backdrop for the wealth of flora and fauna found here.
 
One of the most eyecatching sights along these cliffs is O Seixo Branco, a vein of white quartz that was even used as a navigational reference by sailors, as was A Marola, a nearby islet that marked the limit between the still waters and the open seas, giving rise to the saying: Quen pasou A Marola, pasou a mar toda, suggesting that sailing past A Marola is as difficult as crossing the whole ocean.