An impressive chasm on the highest mountain of Portugal. Lake Covão back Conchos, located on the highest chain of Portuguese mountains, Serra de Estrela hosts a giant hole ... This hole is actually an artificial dam built in 1955. In a circumference of 48 meters and a height 4.6 meters, the dam of Lake Covão back Conchos was conducted to collect the waters of the river Ribeira das naves to route them to the lagoon, Lagoa Comprida. The waters cover a distance of 1519 meters. Portuguese, Daniel Alves has recently achieved impressive aerial images using a drone.