The Cavallers swamp is a reservoir belonging to the Noguera de Tor, created by a dam located in the town of Vall de Boi, in the Alta Ribagorça.
The dam was built in 1960. It is located 1784 m above sea level and its dam, 70 meters high and 360 meters long is the type called buttresses.
In the picture you see the swamp from the north ... and my wife resting.