Martinho da Arcada
Open since the 1700s, this café under the arches overlooking Praça do Comércio is thought to be the oldest in the city and was a favorite of archetypal Lisbon poet Fernando Pessoa. There's a formal dining space inside, with plenty of well-prepared traditional dishes on offer, but the real appeal is sipping a coffee on the flagstones and watching Lisbon life go by. For a quick bite, copy the locals and order a miniprato (a smaller serving of a main, from just €7.50), either at the counter or seated in the café section.