An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

This bridge made famous in a novel and on-screen wasn't actually built over the river Kwai.

Six times a day a train runs right through the middle of this Thai street market, sending vendors scrambling.

The vast chamber inside this abandoned cooling tower looks like something out of a sci-fi dystopia.

This abandoned Belgian fortress is purposefully being left to nature.

The only pollutant in the clear blue water is sunscreen.

WWI hospital ship lost in a cyclone turns up on the coast of Fraser Island, where she remains rusted and forgotten.

A statue of the beloved storybook character stands in front of the building in which her creator was born.

A huge stone pyramid built for fun.

Originally made for a fruit festival in the area in 1998 this was then erected outside the railway station and is now one of Australia’s iconic “Big Things” right at the side of the highway.

A giant Australian fruit and tropical farm.

This small Australian town is considered home to the "Yowie" or the Aussie Big Foot.

This abandoned railroad tunnel is now home to a micro-colony of bats and a ghost train.

A colorful sculpture of an Australian symbol patrols an otherwise ordinary traffic island.

The pillar of this bridge contains a small home and underneath, a ballroom.

Started nearly 100 years ago, this science experiment just keeps on going, ever so slowly.

A tree planted by Marie Curie is treasured by the Radium institute that she set up.

This biographical museum honors the groundbreaking scientist at her birthplace in Warsaw.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

A curious collection dedicated to human and animal anatomy and pathology.

This 22-floor tower's Skydeck offers panoramic views of Amsterdam.

This derelict superstructure was a very important warning system for the Soviet military.

One of the most poignant ruins of the Chernobyl nuclear disaster, the local football team's stadium has been quickly reclaimed by nature.

This attraction was abandoned after the Chernobyl disaster.