A line of disused military bunkers built to defend against Nazi invasion lies hidden on the outskirts of the city.

The alpine falls where Sherlock Holmes apparently met his demise can actually be visited.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

The final resting place of the "father of special effects."

Noirish green neon marks the location of one of the oldest private detective agencies in France.

A subterranean shelter remains intact under a busy Paris railway station.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

The oldest stone house in Paris was built by its most famous alchemist.

The macabre collection of Jacques Sirgent, an expert scholar on the undead and all of their trappings.

One of the greatest movie directors of all time lived and worked in this London flat from 1926 to 1939.

This long-hidden space above Westminster Abbey now displays the battle gear of the legendary King Henry V.

This Viking gravestone carved in a rare runic style was dug up from a London churchyard.

Remnants of cells from the most notorious London prison may lie in the basement of a rare Victorian Gin Palace.

The remains of Crystal Palace Great Exhibition of 1851.

Remnants of a Victorian garden feature sitting in public woodland.

Rebuilt remains of a temple to Roman god Mithras.

A labyrinthine network of chambers with a storied past hides below Edinburgh's South Bridge.

Summer in Scotland begins with a spectacularly wild and colorful event rooted in ancient pagan traditions.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

These stark white cliffs were spat up by the sea and are slowly being retaken by it.

A fantastic castle rumored to be the birthplace of King Arthur.

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

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