Marechal Carmona Dam, also known as Idanha Dam, Idanha-a-Nova Lake and Idanha-a-Nova Reservoir, is a dam on the Ponsul River in the municipality of Idanha-a-Nova, District of Castelo Branco, in Portugal. Named after Óscar Carmona, a Portuguese Army officer and politician, it is a gravity type dam located besides a tight granite throat over the Campinas, in Idanha-a-Nova municipality. The dam began to fill in 1946 during Estado Novo. A few kilometres outside the town of Idanha-a-Nova lies this dam which completely transformed the landscape of the valley and separated the two Idanhas – the Nova (New) and the Velha (Old). The reservoir now contains a large artificial lake that is ideal for canoeing and other water sports. In summer, the river beaches are a perfect place to cool off. Sports and leisure activities in its reservoir include fishing, swimming, sailing boats and windsurf.[1] The music and culture festival Boom Festival takes place on its banks every other year.