Val d'Aran, a small valley (620.47 km2) is a comarca (county) in the northwestern
part of Catalonia, which is an autonomous region of Spain. Most of the valley constitutes
the only Catalan territory on the north face of the Pyrenees, hence the only part of
Catalonia whose waters drain into the Atlantic Ocean. The region is characterized by an
Atlantic climate, due to its peculiar orientation, which is different from other valleys in the area.

The Val d'Aran borders on the North with France, with Aragón on the west and
with the Catalan comarques of Alta Ribagorça to the south and Pallars Sobirà
to the east. The capital of the comarca is Vielha, with 3,692 inhabitants (1996).
The entire population of the valley is about 7,130 (1996). The chief river is
the Garona, which descends through Gascony to the Atlantic. The Noguera Pallaresa,
with its head only a hundred meters from that of the Garona, flows the other way,
toward the Mediterranean.

The valley used to be without direct communication with the south side of the
mountains during winter, until the construction of a tunnel, opened in 1948.
Spanish Republican guerrillas (supporters of the Second Spanish Republic, the
losing side in the Spanish Civil War) controlled the area from the end of World
War II until the opening of the tunnel.