immagine: 

The village of Ridracoli is characterized by the presence of a humpbacked bridge that leads to an ancient palace, now used as a hotel. Adjacent to the inhabited area stands the recent water museum, "Idro", with interactive areas and displays. Going up the valley, you can admire the ruins of a medieval castle and, proceeding further, will reach the imposing dam built in 1982 in order to supply energy and water to the towns of the Romagna plain. Upstream of the dam, the basin, whose waters have flooded three branches of the valley, is framed by steep slopes incised by numerous valleys, where the arenaceous outcrops alternate with the wooded strips. Seen from above, the Ridracoli Lake has a narrow and long shape similar to a fjord, and creeps for over three kilometres into the Bidente valley.

http://www.atlantide.net/idro/