Largo do Carmo is a very charismatic square in downtown Lisbon.
Once you climb one of Lisbon’s hills, you’ll reach a place whose distinct elements tell you many stories that you can listen to for hours. Back in 1755, the convent that it harbored became a beautiful ruin, currently used for cultural purposes and never completely rebuilt. At the center of the square, a modern fountain shows you how the whole city was rebuilt after that tragedy.
Years later, Largo do Carmo, most specifically the military quarter it hosts, took an active part in the magnificent history of Portuguese democracy: the Carnation Revolution, on April 25th, 1974. Here, the Prime Minister of the dictatorial government capitulated.
Besides its historical legacy, the Largo do Carmo is an intersection and departure point for several other spots in Lisbon, such as Rossio, Chiado, Miradouro S. Pedro de Alcântara (one of many viewpoints) and even many places where you can eat some local dishes or just enjoy a drink.
I always end up walking by the ruins of the convent and getting a Moscow Mule at Topo Chiado facing the old Castle and the Elevador do Carmo (or Santa Justa), which is especially lovely at night.
It might be hard going up, particularly on hot summer days, but it is for sure worth it. The best thing about it is that going down there are many itineraries to choose from, so you will always end up seeing lots of different and nice buildings, people and places.