5. Campo de' Fiori
This centro ‘storico (historic center) piazza dates from the Renaissance, and its busy morning market has been operating since the 19th century. Colorful stalls burst with local vegetables and slender bottles of limoncello and olive oil. Trattorias with outdoor tables surrounding the piazza are lively places to people-watch — perhaps in the evening, while sipping chilled prosecco. It wasn't always fun and games here, though: the piazza was once used for public executions, and a grim statue of philosopher Giordano Bruno marks his burning at the stake in 1600.