Due to its particular position at the Setúbal Bay, near the mouth of the Sado River and its natural harbour, it is an important fishing town.

In the 17th century the fort Fortaleza de Santiago was built along the beach, as part of Portugal's coastal defence.

A tourist travelling to Sesimbra can appreciate its beaches, traditional fish restaurants and the Arrábida National Park.

It stands on the spot where king Sancho I built a Romanesque chapel in the early 13th century, leading to the creation in 1388 of the parish of Nossa Senhora do Castelo de Sesimbra.

On the left side of the choir stands in a niche the gilded and polychromed statue of the Madonna of the Castle on a giant shell.

[6][7] Discussions regarding membership are also in hand with three further towns (Agros in Cyprus, Škofja Loka in Slovenia, and Tryavna in Bulgaria).