Cold war icon and onetime "hole" in the iron curtain.

This "floating railway" is one of the world's oldest monorail systems.

Copenhagen's celebrated theme park and gardens.

A natural wonder in south Denmark.

This monument to those fallen in the World Wars is accompanied by a U-boat that Germany bought for a Deutsche Mark.

The world's first and only three-segment bascule bridge folds up into the shape of a capital "N" to let boat traffic through.

Hitler's bleak vision of relaxation still stands as a mostly abandoned 10,000-room resort complex.

These beautiful objects represent beautiful ideas.

Hamburgers are intensely proud of their tunnel beneath the river.

Goethe's "Faust" was inspired by these rock formations known as the "Devil's Pulpit" and "Witches' Altar."

On the highest peak in the Harz Mountains, science and the occult faced off in a failed attempt to turn a goat into a boy.

Ruins of a German castle on top of a towering stone pillar.

This Dresden church was purposely rebuilt Protestant after being demolished in World War II.

The site of a concentration camp where inmates were made to take part in one of the largest counterfeiting operations in history is now hauntingly empty.

Explore the complex ecology of this multifaceted nature preserve by riverboat.

Terrifying derelict military hospital once housed a recuperating Hitler.

Solar observatory doubles as a daring display of Expressionist architecture, much to Einstein's chagrin.

The 1936 Summer Olympics site is a crumbling remnant of sportsmanship and a history its host country would like to forget.

A quaint Russian village in the middle of a German metropolis.

Germany's Glienicke Bridge has a shady history of clandestine meetings, espionage, and spycraft.

This Berlin island is home to a flock of free-roaming peacocks, as well as a historic ivory folly.

This conical hill was built as a testing ground for an engineer known as the Glider King.

A 12th-century fortress containing some of Berlin's oldest buildings.

An abandoned NSA listening post on Berlin's "Devil's Mountain."