Italian cave with exceptional acoustics and an unsavory history.

Bell tower juts out from a village buried under a lake.

More sculpture than building, this architecturally significant temple was built on the spot of Saint Peter's crucifixion.

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

The remains of a town so thoroughly destroyed by French forces that the citizens simply left.

This immaculate and historic water garden culminates in a massive stone dining table with an inset fountain for chilling the wine of the Cardinal's guests.

An Italian hillside ghost town.

Architectureal fantasy quarter of Rome.

These spectacular ruins were built by Spanish padres in the 17th century.

Solitary monument dedicated to the beauty of nature.

Ruins of a 10th century church tucked away deep in a botanical garden.

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.

This 16th-century monastery has been turned into a surrealist architecture compound.

Renaissance villa and gardens complete with a tormented colossus.

Stalactites and stalagmites in a beautifully lit cave.

An alchemist's "magic door" stands in the middle of a Roman park.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

A small island less than half a mile from Venice is a forbidden island with a dark and twisted past.

A 16th-century horror show built in a lovely Italian garden.

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

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

Pompeii's less famous neighbor is still revealing her secrets.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

The fairy tale castle of the "fairy-tale king."