Amsterdam's former hotspot for public executions and dissections.

One of Amsterdam's narrowest houses is located right across the canal from its widest.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

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

A unique configuration of blown glass can be found inside this hotel lobby.

This living legend of maritime history is enjoying a second life.

This futuristic building is yet another architectural wonder in Dubai.

The world's largest frame offers spectacular views of the city's past and present.

This indoor ski resort has a mountain contained inside a mall.

A preposterously luxurious hotel with gold-plated iPads, Rolls Royce chauffeurs, and a staff that trains by watching "Downton Abbey."

A faithful reproduction of Al-Jazari's enormous water clock.

This artificial archipelago was supposed to resemble a map of the world.

The last bastion of Roman presence north of the Alps looms over a German town.

The birthplace of Karl Marx is now a museum dedicated to the communist revolutionary's life and work.

The intricate geometry inside this Baroque-style dome was designed to create "terror of the human soul."

This building has a giant piercing through one of its corners.

This fountain is dedicated to the workers who perished constructing the Fréjus Rail Tunnel.

Nestled in the heart of Milan is a real wunderkammer of morbid curiosities.

This curious building hides eclectic details like medieval gargoyles alongside naked angels and Art Nouveau mosaics.

The train platform where Jews were sent to concentration camps is now preserved as a Holocaust memorial.

Artistic tombs, monuments, and a beautiful "Hall of Fame" lurk inside this cemetery.

The mark of the Devil's horns on a marble column in Milan.

The secret medieval communication system will whisk your words above the noise of the crowd.

A brutalist gem towering over the heart of Milan.