Berlin's old airport.

A castle from the Holy Roman Empire that hosts traveling youth... in its stables.

The "Prussian Versailles" that is as glorious today as when it was built.

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

The fairy tale castle of the "fairy-tale king."

This life-size replica of the Statue of Liberty's flame is also a tribute to Princess Diana by default.

This bridge was constructed from the rubble of the infamous Bastille.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

Once the tallest building in the world and the site of "the highest dinner ever held in New York" this building now holds the most expensive penthouse in the city.

This castle-like building in Manhattan helped destigmatize cancer in the 19th century.