The smaller of the three towers of San Marino is a former prison inaccessible from the ground level.

Small on the outside, big on the inside, this church is an astonishing act of visual deception.

An ossuary built in 1210 to collect bones from the Ospedale Maggiore of Milan.

Italian director Pier Paolo Pasolini fell in love with this lonely 13th-century tower while making his most famous film.

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

A lavish 16th-century mansion filled with spectacular staircases, fantastic frescoes, and gorgeous gardens.

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

Geothermal waterfalls in Tuscany.

This quaint Italian town keeps losing ground as the sides of its plateau slowly erode.

This high-speed test track is popular with car manufacturers, speed freaks and orbiting astronauts.

A fascist-era rural village abandoned since the early 1980s.

It's believed that these columns marked the end of the Via Appia.

The steel cable lets adventurers zoom between two mountain towns at speeds of up to 75 miles per hour.

An impressive bridge over a ravine also served as an aqueduct.

Visit a surreal landscape so otherworldly NASA actually used it to train the Apollo 17 crew.

The chefs at El Diablo use heat generated by an active volcano to cook the food.

This beautifully verdant lagoon is tucked below a massive volcano in a crater atop a black pebble beach.

Partially collapsed lava tube and cave system complete with concert hall, underground pond, and unique albino crabs.

The oldest-known example of a historic architectural style recognized by UNESCO.

Legend says these colorful, invasive residents are the descendants of birds released by Jimi Hendrix.

The Tudor-style cottage in the middle of the square is not quite what it seems.

An architectural oddity hides in plain sight on this iconic London bridge.

Metro station with a claim to rock n' roll fame.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.