Largo do Carmo
Time Out says
The construction of the centre fountain started in 1769 as part of the urbanisation ordered by the First Marquis of Pombal. Around it are a number of interest points from various eras. It’s on Carmo Square that the ruins of the Carmo Convent, built in the 14th century, still stand, and now house the Carmo Archaeological Museum. You should also check out the quarters where Prime Minister Marcelo Caetano took refuge during the Carnation Revolution that overthrew his government.