A fiery crater has been burning in the Karakum Desert since 1971.

This gorgeous reading room houses the oldest and largest art history library in the Netherlands.

A Portuguese Jewish cemetery filled with stunning grave monuments that date back to 1614.

This unusual elevator doesn’t stop or slow down.

Dating back almost 400 years, the oldest public collection library in the United Kingdom was once the study hall of Karl Marx.

A Victorian Gothic masterpiece housing a world-class collection of rare books and manuscripts.

The Bristol Camera Obscura housed in an ancient windmill.

A well-preserved network of cavernous tunnels have spent silent centuries removing Toronto's waste.

The Incredible Hulk, Yoda, Mulder and Scully, and many many others watch over the mean streets of Toronto.

A meandering boardwalk across the bogland leads to a "stairway to heaven" with sublime views.

One of the last doorless, continuously moving elevators still in use in the U.K.

The largest cave chamber in Britain—big enough to fit a whole cathedral inside.