The initial idea of ​​1959 to create a swimming pool fed by the tides of the Atlantic Ocean, was abandoned for hygienic and topographic reasons. Engº Bernardo Ferrão had proposed a 20x33m rectangular pool parallel to a protection wall. However, during a project that was thought to be simple, the need arises to think about the urban framework of the work with the surrounding landscape. At this stage, a young architect of 26 years is called. Bernardo Ferrão knew Siza Vieira from collaborations with his brother, the architect Fernando Távora. They decide to hire the young architect who was working on another pool project for Quinta da Conceição (1958-65). Siza Vieira, 26 years old at that time, proposes a large lake embedded in the rocks. Having been refused by the municipality, she then proposes the adaptation of the rectangular pool to the topography of the local rocks. Bernardo Ferrão presents the final project in March 1960, and construction begins, following the idea of ​​Siza Vieira. In 1963-64 the second phase was built: children's pool, changing rooms, access ramp and a small snack bar.

The pool complex in Leça consists of changing rooms, a café and two pools, one for adults and one for children. It is located between the Atlantic Ocean and the access of the highway that follows the coast, but it is implanting almost completely out of sight. When sinking the building behind the highway, there is a disconnect between the pools and the city's infrastructure. The pools reach the ocean and mix with the natural pools present along the coast.