The skeletal frame of a decommissioned gas-pumping station offers breathtaking views of greater Berlin.

A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.

This classic restaurant features a gorgeous mirror-clad room.

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

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

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

A towering monument to war, located on a beautifully peaceful hill.

Berlin's old airport.

An eerie, derelict amusement park in Berlin.

A curious collection dedicated to human and animal anatomy and pathology.

This vast collection of smoking pipes from across the world spans centuries.

This unattributed sculpture in Amsterdam is hiding in plain sight.

A public urinal so pretty, it was declared a national monument.

Amsterdam's Red Light District leaves little to the imagination.

In the days before house numbers, these colorful signs held clues about various buildings' purposes.

This basement museum explores the art and artistry of fascism.

Amsterdam's narrowest house facade is a monument to 17th-century tax evasion.

A floating cat sanctuary on an Amsterdam canal.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

The last of Amsterdam's original sea level markers remaining in place.

Seven mini rowhouses fill the gap between 54 and 70 Westerstraat.

This pirate-broadcasting-tower-turned-restaurant played a rebellious role in the history of Dutch television.

The place where Czar Peter I of Russia resided in 1697 during his Grand Embassy.

Colorful and chaotic stacked hotel in North Holland.