The building of the Olhão House of the “Compromisso Marítimo” (the “Maritime Agreement” mutual society) was funded by the local fishermen. It was built in the 18th century and has two floors and roofs with four sloping sides, typical of Algarve architecture.
On the façade, a niche with a statue of Nossa Senhora do Rosário (Our Lady of the Rosary) can be seen.
This historical building currently serves as the city’s museum. Here visitors can see an exhibition of archaeology, and others about fishing and the history of the city of Olhão.