A 1,215-foot tunnel transports pedestrians beneath the River Thames.

Rebuilt remains of a temple to Roman god Mithras.

A subterranean ice warehouse that has lain hidden beneath central London for over a century is now open to the public.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

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.

Hidden beneath the streets of London is a secret subway that only carried mail.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

Rising from the sea like a stone monster.

This fantastical waterfall is hidden in a cave located in a cracked cliff.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

Iceland's largest lagoon is home to stunning multi-colored icebergs.

This volcanic cave lake is essentially hard proof that Iceland is the most magical place on Earth.

Staves, storm-calling, and of course, necropants.

The unique waterfall in Iceland's south features a backdrop of geometric black lava columns.

Medicinal spa created with the discharge from a geothermal energy plant.

This macabre painting of a Shakespearean scene looks like something out of a nightmare.

This stunning mountain lake was named for a pair of tragic lovers whose statues stand at the center.

One of the cave cities of Crimea, built by the Goths in the sixth century.

This futuristically sylvan church is a glass-enclosed marvel of modern architecture.

A moody and picturesque riverside ruin overgrown with vegetation.

The train platform where Jews were sent to concentration camps is now preserved as a Holocaust memorial.

In Northeastern Iceland lies something of an oxymoron: a steaming desert.

The Hanshin Expressway goes right through its 5th, 6th, and 7th floors.