Edifício Matarazzo São Paulo

The seat of São Paulo's city government sits inside this 1930s neoclassical 'palace' designed by Italian architect Marcello Piacentini (who is well-known for his fascist architecture in Rome). The 14th-floor rooftop gardens – practically a jungle, really – are open to the public for free on a first-come, first-serve basis. Bring ID, show up at least an hour in advance and set aside an hour for the visit. Tours are limited to 10 people per hour.