Suffocating dogs was a common spectacle in the fumes of this noxious cave.

A surreal botanical garden with an even more surreal tour guide.

An unusual "skull with ears" sits in the crypt of this small church tucked away at the end of a narrow alley.

The remains of the left arm of the levitating philosopher-saint are kept in a 13th-century Neapolitan basilica.

These "anatomical machines" are only one of the many strange items in this Italian crypt.

This shining multicolored metro station deep under Naples is said to be the most beautiful in Europe.

A centuries-old forgotten underworld lies beneath Malta.

Risk arrest while partying to fund art.

A burial ground of rusting metal grave markers.

The home of aviation trailblazers, in a remote corner of the big city.

What if all public housing projects had been designed by "the Pygmalion of modern architecture," not only their prototype?

This extensive collection of vintage Soviet cars is the only one of its kind in the Caucasus.

This extraordinary, multi-pillared monument depicts the fascinating history of Georgia.

Unusual building appears to be haphazardly built from randomly piled bricks.

Luxury hotel turned into a refugee camp, then turned back into a luxury hotel.

The world's first floating farm is staffed by one human, three robots, and 35 cows.

The Netherlands' first car tunnel has an unusually rectangular shape.

These slanted cubic abodes are a creative if odd solution to a zoning pickle.

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

A large collection of solar and night-time telescopes dot a small area on the Teide mountain range.

Lava stone structures possibly dating back to the 19th century may have been a stopping point for voyagers between ancient Egypt and the Mayan Civilization.

Bits of flat terrain surrounded by cliffs make one of the most beautiful landscapes in the Azores.

This historic hydroelectric power plant in Japan has been preserved and is open to the public.