This building is a Lavadouro. Often, these buildings are trashed with random graffiti tags. Lately, the Union of the Carcavelos / Parede parishes are giving those buildings a nice layer of paint, with a wink to the history of a Lavadouro.
Lavadouros have traditionally been places where ladies (it’s almost always women) come to wash clothes, chat with neighbors, and sing.
These days, most modern Portuguese houses are outfitted with washing machines (if not clothes dryers). Those that don’t have a washer will pop down to the Lavandaria (laundromat).
However, even if they are infrequently used, many traditional wash houses still stand, complete with concrete wash basins and a ridged scrubbing deck.