Sheltered in the Lonja de Comercio building with seating outside in Plaza de San Francisco de Asís, El Mercurio flirts with elegance (waitstaff in waistcoats and ties) and is the first thing most cruise passengers see when they stumble onto dry land. It serves cheap lunches (Cuban sandwiches) and more substantial dinners (lobster and steak tartare). The former are the safer bet.
El Mercurio
Habana Vieja