Living trees form the structure of an open-air palace.

These bronze pamphlets remember a remarkable group of Germans who fearlessly opposed the Nazis in the very center of their power.

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

Berlin's old airport.

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

A small but immensely extravagant palace built by the "Night King."

Beneath the impressive baroque cathedral that rises from the center of Berlin lies the largest collection of Prussian royals in the world.

A long spiraling walkway winds through the woods, and around a copper beech tree at the center.

This historic stone bridge has an entire neighborhood clinging to its sides.

This German fountain of a legendary apple wine-loving drink thief will spit on you.

Carved fountains poignantly placed in parks and in front of special monuments.

Someone loved this song enough to carve all of its lyrics onto a tree trunk in a Berlin park.

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

"The most colorful grottoes of the world.

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 stairway to heaven, or to nowhere at all.

The patron saint of spinsters grasps a container of dried blood.

What started as a tongue-in-cheek shrine is now a full-blown museum celebrating "The Hoff" and his longtime love affair with Berlin.

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

A striking 12th-century-style castle built on the edge of a cliff.

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

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

Art and a pun, all in one.