Forte di Belvedere
Built in the 16th century, the fortress was designed to demonstrate the power of the Medici family and to protect the center of the city. Not many people know that Galileo visited the fortress and completed some of his important studies here. Nowadays, the Belvedere holds incredible exhibitions and cultural events, not to mention the spectacular view of Florence. Also, Kanye West and Kim Kardashian got married here in 2014.
The entrance is free of charge.