The village of S. Martinho do Porto, Parish seat of the Municipality of Alcobaça is the most famous and important bathing area in the county. Its beautiful bay, unique in the country and in Europe with a perfect shell, offers you a unique use for bathing and water sports.

The bay, located arround 19 Km from Alcobaça and about 100km from Lisbon, is the last vestige of the old gulf that stretched to Alfeizerao until the sixteenth century.

with 3 Km of beach, this bay with calm waters, has a intlet to the sea with 250 meters opening between the hills of Santana south and north of the lighthouse.

The village of S. Martinho do Porto develops in the amphitheater from the Chapel of Sto. António to the pier and the beach, following the avenue to the dunes of Salir do Porto.

Due to its characteristics, the bay of São Martinho do Porto was one of the main ports of the country by the end of the last century, been gradually losing its importance with the advent of steamships. Nowadays it's an important marina and collection center seaweed underwater.

The whole area is still possible to observe bird species such as swifts real unusual blackbird blue, kestrel, redstart, several species of gulls, crow, etc.