El Pas de la Casa is a ski resort (part of the Grandvalira resort), town, and mountain pass in the Encamp parish of Andorra, lying on the border with France. Its name literally translates as "the pass of the house" and refers to the fact that until the early twentieth century there was only a single shepherd's hut overlooking the pass. The pass marks the watershed of the Pyrenees, being the only point in Andorra where water drains into the Atlantic Ocean, and is the source of the Ariège river.