For centuries the plaza has been a hive of activity and a focal point of the city. Amongst the restaurants, markets and vendors at its fringe is the oldest cafe in Lisbon - Martinho da Arcada - which was established in 1782.
It was originally the site of Portugal’s most important palace, the Paço da Ribeira, before it was destroyed by the earthquake and tsunami of 1755.
On three sides, the plaza is surrounded by yellow Pombaline-style buildings, with white arches lining the façade. The southern aspect looks out over the harbour and the Tagus Estuary.
The square reflected the wealth and affluence of Portugal during the late 18th-century. Its proximity to the harbour meant that it was, and still is, a symbolic entrance into Lisbon, as well as a meeting place for merchants and traders arriving by sea.