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

An eerie, derelict amusement park in Berlin.

Once standing on solid ground, this slender beacon is a victim of the very shoreline it was charged with announcing.

Man-made mineral caves house massive bat colony.

The gutted remains of this Estonian mansion are a monument to a tragic love.

This disappearing geyser has been attributed to witchcraft, but really it's all about rainfall.

Mysterious craters may have been home to an ancient cult.

The ruins of an Estonian prison are drowning in the quarry lake where the convicts were once forced to work.

"There's nothing there," and other lies the KGB told us.

Naturally formed rock city in Poland.

A program of Communist glamour in post-Stalin Poland is preserved in this colorful museum.

The site of the first battle of World War II.

This uber-quaint Polish village is known for its habit of painting elaborate floral motifs on just about everything.

A fairytale Gothic castle steeped in Nazi treasure conspiracy theories.

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

Beneath Kraków Old Town's main square lies a hologram-filled medieval market vampire graveyard wonderland.

Real bones which are said to have belonged to a Polish dragon.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

This Nazi ruin was the site where Hitler was almost blown up by a suitcase bomb.

An underground city of salt.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

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

Countless stories attempt to explain Poland's mysterious J-shaped trees.

Nordic giants resurrected from the sea and restored to their former greatness.