A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

Museum dedicated to the terror regimes of Hungary.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

The walls of Germany's Parliament still show the scars of the Red Army takeover in World War II.

The site of the famous Nazi book burning campaign of 1933 remembers its "Night of Shame".

Where once there was a train station bathroom, there is now this German burger joint.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

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

This Croatian fairytale castle is slowly falling apart thanks to years of neglect.

Longest fortress system anywhere in Europe.

Large, airy hallways hide within an impenetrable fortress that beckons urban explorers.

Humble beginnings for one of the world's most famous scientists.

Where the lovelorn find a home for their sentimental keepsakes.

A musical instrument played by the sea.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

Bridge that died in war and was resurected.

On any given day this sprawling market houses literally tons of government-regulated gold, gems, and precious metals.

This mysterious abandoned fort looks like something pulled right from Arabian legend.

This enormous sports car themed amusement park is home to the world’s fastest roller coaster.

This artificial archipelago was supposed to resemble a map of the world.

This indoor ski resort has a mountain contained inside a mall.

A preposterously luxurious hotel with gold-plated iPads, Rolls Royce chauffeurs, and a staff that trains by watching "Downton Abbey."