Praça Luís de Camões is not the biggest square in town, nor is it the prettiest, IMO, but throughout our visit (during Carnival), it sure was the liveliest. Lots of street performances, including music, dancers, those fake-statue people, and commercial promos with freebie giveaways. My guess is that the location of this square (in the Barrio Alto neighborhood, very close to the border with Baixa-Chaido), makes it a huge traffic-way for Lisbonites commuting from work neighborhood to home neighborhood, and tourists whose hotels and hotspots are all around, thus it's a great place to grab a lot of people's attention.
Surprising to me, there is vert little public seating in this square, but people are content to hang out standing, gathering around performers, just hanging out. Personally, without benches, it didn't feel very relaxing to be there, as entertaining as it was. Lisbon is full of steep hills (stairs), and very few subway stops in the popular cultural areas, thus you walk nonstop all day, and I needed a bench to unwind. There are just a couple of cafes off of the square, and those (seated) people seemed much more reposed. Unfortunately, the standing crowds around the entertainers make it impossible for the people at cafe tables to really see any of the action.
There is a cable car that stops on the square, as well as a bus stop. Lots of shopping in the Baixa direction of the square, and famous nata shop, Manteigaria, has a location on one corner of the square.
Two nearby churches worth seeing, just off the square, are Basílica de Nossa Senhora dos Mártires and Igreja Nossa Senhora da Encarnação. read more