Be it nature, art, or abandoned military architecture this eclectic German "museum" has you covered.

Geometry and mystery come together in an epic show of octagonal masonry.

A rocky sea serpent hides caves, blowholes, and a spectacular natural bridge.

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.

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

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

A island reachable by a causeway at low tide is possibly one of the earliest Western European locations to be identified in text.

A whimsical tower with a spiral staircase, inspired by the Space Age and the Möbius strip.

The hidden "ballroom" under a mansion lake was built by a criminal who ate a cyanide pill during his trial.

This unusually shaped mountaintop tower looks like a UFO floating over the city.

The one-time stronghold of the noble Douglas family, now home to ghost sightings and nesting birds.

Vortex-shaped aquarium hosts Europe's largest school of piranhas and other ocean creatures.

A petite castle folly in the English countryside.

The real life Hobbiton, this sheep farm has been forever transformed since being built for The Hobbit film series.

A whimsical and twisted animatronic monster tour beneath the streets of Berlin.

A metal tree emits eerie, melodic notes on top of Lancashire's Crown Point.

World's largest working waterwheel has been around for over 150 years.

Huge winged monument in the United Kingdom.

Northern Ireland's Brobdingnagian stepping stones.

A 30-acre garden inspired by the principles of modern physics.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

17th century streets hidden under Edinburgh were once a breeding ground for the black death.

One of Scotland's most important modern structures, it just made the '100 Most Endangered Sites' list.

The largest ice cave in the world is thought to be the entrance to hell according to Austrian legend.