Santa Maria del Fiore (Il Duomo), Florence, Italy

As the city's skyline symbol, the legendary Duomo is famous above all for its dome: Filippo Brunelleschi's Renaissance masterpiece, completed in 1436, created a double dome shell so that the dome is entirely self-supporting. It still stands as the largest masonry dome in the world, containing over 4,000,000 bricks! Climb to the top (all 463 steps) to get an unforgettable panoramic view of the city, which has changed little in the past 500 years. Construction started in 1296 on the site of the Roman basilica of Santa Reparata, of which there are still visible remains with a design by the great Florentine architect, Arnolfo di Cambio. The existing neo-Gothic facade was added in the 19th century by Emilio De Fabris. Covering a massive 3,600 square meters, the frescoes inside the dome depict the Last Judgment, painted by Giorgio Vasari and Federico Zuccari. If you can stand the throngs of people and get a good spot early, come on Easter Sunday for the Scoppio del carro (Explosion of the Cart) where a oxen-drawn cart stuffed with fireworks comes from Prato to the center of the city and ignited.