The village of Sem in Vicdessos Valley, lies at the foot of Ganchette peak at about 1000 m altitude. The village's history is intertwined with that of mine rancid. Iron mine, operated for nearly two millennia, a low furnace discovered some years ago shows that it operated in the 3rd century. The mine, which the count of Foix gave the enjoyment of ore miners, operated until 1930.
Today the village has only about 25 permanent residents, but summer is filled with festivities organized by various associations and the municipality.