A small island that was once a key Axis fortification during World War II.

Journey through the ruins of this ancient Roman temple dedicated to the god of war.

An enchanting work of outsider art, full of whimsical sculptures and carvings.

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

This massive subterranean fissure is known as the "underground Grand Canyon."

A Museum of Psychiatry in a still-operating mental institution.

The most visited, and possibly most controversial, museum in Germany.

Started as a kitchen garden, now the second largest botanical garden in the world.

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

The ruins of an 11th-century Norman castle with a rare, perfectly circular shape.

Besieged by war, this castle ruin has crumbled into a peaceful picnic spot.

One of the oldest and certainly best preserved Cistercian abbeys still in existence.

It is said the legendary wizard once lived in this sea cave beneath Tintagel Castle.

This iconic Peak District ridge was once one of the busiest roads in medieval Britain.

This Gothic Revival castle used as a shooting location for "The Secret Garden" and other films.

This iconic 1,000-year-old medieval castle is a favorite of the film industry, most notably as the location for Hogwarts in Harry Potter.

An unusual round church in London with a Templar past.

The world's largest collection of witchcraft regalia.

Winding paths and ramshackle mausoleums in the oldest "park cemetery" in London.

This collection of illusory paraphernalia has been culled from the history of London's premier magician's club.

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

Legend says a witch conjured the world's third largest whirlpool to protect Scotland from a nasty pirate.

A remarkably well preserved tower dating all the way back to the Iron Age.

A red sandstone freestanding monolith rises out of the sea in northern Scotland.