A small window on Via Piella offers a lovely and rare peek at Bologna's lost canals.

The world's oldest surviving anatomical theater, where "the dead are pleased to help the living."

A once-luxurious, now abandoned hotel in the Italian Alps.

These delicate sand pyramids look like naturally occurring gothic spires.

A sinister pyramid in the Frari contains the heart of the famous neoclassical sculptor.

Gigantic mosaic sculptures of the figures on Tarot cards fill this colorful Tuscan garden.

This abandoned Brutalist treehouse is a hidden architectural relic.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

Gorgeous views of Italian mountains and valleys form the backdrop of this unique open-air theater.

The city of Palestrina was built around this magnificent terraced sanctuary dedicated to the pagan goddess Fortuna.

The highest waterfall in Italy is only "turned on" five times a year.

Stumbling upon this whimsical wooded garden is like stepping into an enchanted forest full of philosophical musings.

Nestled in the heart of Milan is a real wunderkammer of morbid curiosities.

An open-air museum in a mountain valley features works designed to blend in with—and disintegrate back into—their natural surroundings.

A domed disco abandoned since the '70s now attracts artists and explorers under its unique roof.

This winding road through an Italian canyon may be the most scenic drive in the world.

An ancient artistic garden parlor full of hidden water wonders.

This Tuscan lake hides a 13th century town that is still visible when the water recedes.

The Sighignola summit on the Swiss border offers views so breathtaking it's been named one of the most beautiful places in Italy.

This real life asylum of horrors is now an abandoned ruin that hides the unbreakable code to one patient's insanity.

Medieval town turned hippie commune, once home to the secret foreskin of Jesus Christ.

The location of the last witch trials of Italy, known as "The Salem of Europe."

Natural cathedral designed by Italian artist Giuliano Mauri.

This domed temple was built in a hidden cave mouth as a refuge for sinners seeking absolution.