Trullo buildings in Alberobello, Apulia, Italy (© Feng Wei Photography/Getty Images)

If fairy tales had architects, they might've come up with something like Alberobello in Italy. But instead of magic wands, it was limestone, mortar-free masonry and—according to some theories—a bit of tax evasion that built this town's signature homes: the trulli. These are whitewashed stone houses topped with dry-stacked limestone roofs shaped like upside-down ice cream cones. It's an ancient building technique, and in this case, a clever one. Alberobello's trulli aren't hidden one-offs. Entire districts—like Rione Monti and Aia Piccola—are packed with these quirky structures. Some are still lived in, while others have been transformed into cafés, souvenir shops and pint-sized museums. You'll even find a church built in trullo style.