Black Lake of Urbión, Glacial lake in Sierra del Urbión Natural Park, Spain

The Black Lake of Urbión is a mountain lake in the Sierra del Urbión surrounded by steep granite cliffs and dark water. The landscape around it features dense pine forests that cover the surrounding slopes.

The lake formed during the last Ice Age when glaciers carved a deep basin into the mountainside. This geological process created the distinctive depression where water now collects at high elevation.

The dark waters of the lake influenced Spanish poet Antonio Machado to write La tierra de Alvargonzález, incorporating local folklore into literature.

Access is from Vinuesa along the SO-830 road through the Revinuesa valley; in summer and other busy periods, cars are barred and visitors walk or take buses from Vinuesa. The lake lies at 1,753 m, so weather can change quickly. Wear sturdy footwear and allow extra time for the climb.

Its maximum depth does not exceed 8 metres, though legends claim it is bottomless and figures of 10 or 12 metres are sometimes repeated. The first Sunday of August brings a swimming crossing of the lagoon.