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

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.

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

Soaring over 6,000 feet in the Bavarian Alps, this beer garden was once Hitler's 50th birthday present.

This medieval castle overlooking the Elzbach river looks just like it did hundreds of years ago.

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

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

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

A slice of central Asia in the middle of Berlin.

The most visited, and possibly most controversial, museum in Germany.

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

Started as a kitchen garden, now the second largest botanical garden in the world.

The largest free-standing aquarium in the world resides in a hotel lobby in Berlin.

This futuristic German spa allows visitors to float in a pool of salt water while zoning out to underwater techno.

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

A true Valhalla for cactus and succulent lovers.

Tucked away in the Leiden city hall are a group of works by famed artist MC Escher.

A 'living museum' in Leiden, the oldest of its kind in the Netherlands.

This gorgeous reading room houses the oldest and largest art history library in the Netherlands.

This beautifully designed star-shaped fort was the premier defense system of the late 1500s.

The Bloemen Route, or “Flower Route”, stretches 25 miles through prime Dutch tulip country as a result of “tulip mania,” the world’s first economic bubble.

Oldest Museum of the Netherlands is a true cabinet of curiosities.

Unsurprisingly, Holland is home to one of the most magnificent flower gardens in the world.