Feira da Ladra
It's a classic spot in Lisbon. It happens every Tuesday and Saturday in this square near the National Pantheon and São Vicente de Fora church, which are pretty nice places too. It's not your typical market – you'll find all sorts of random stuff there, from old tiles to antiques and crafts. It's kinda cool just wandering around, seeing what people are selling. Definitely worth checking out if you're into that sort of thing!
