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

When the rain falls, this drain system turns into a musical instrument.

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

A tree-like building perches on its trunk in the Steglitz neighborhood of Berlin.

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

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

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

A sprawling Baroque park with 300-year-old hydro-pneumatic waterworks.

Berlin's natural history museum houses the world's largest mounted dinosaur and the late beloved polar bear Knut.

This World War II bunker now survives as a documentation of the Nazi regime and war crimes.

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

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

A fascinating insight into daily life in the Eastern Bloc.

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

Art and a pun, all in one.

Gardens representing parts of Asia, Europe, and the Mid East are tucked away among the Soviet-style buildings in East Berlin.

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

A narrow strip of land is home to the tallest migrating dunes in Europe.

This set of concrete chambers resonates according to different notes of octaves.

A trio of giant wooden megaphones turn up nature's volume in this Estonian forest.

This striking memorial is one of Estonia’s most controversial Soviet leftovers.

A memorial museum to the political prisoners who were held at Sighet Prison, once one of the most feared places in Romania.

This Transylvanian church has changed its denomination four times.

This hauntingly beautiful cemetery outside a medieval citadel is full of winding paths and ivy-covered graves.