The pool is along a stretch of coastline in Leça da Palmeira and was designed by renowned architect Álvaro Siza Vieira.
The two saltwater swimming pools of Piscina das Marés are sunk into the rock of Leça da Palmeira beach, Matoshinhos, a fishing village north of Porto.
Inaugurated in 1966, it was classified a National Monument in 2011.