The submerged village of Vilarinho da Furna, Portugal

When the water level of the dam is low, it is possible to see the walls of a 2000-year-old village, which was destroyed by an electricity company. The last 300 residents had to leave their homes in 1971 to provide hydroelectricity to the region. It is believed the village was founded by the Romans in the 1st century and the village prospered all that time. Now a museum is dedicated to the lost village in São João do Campo nearby and visitors can explore the lost village on boat tours.