Step back in time and witness the fall of Constantinople.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.

Turkish adventurer antiques in the heart of the Grand Bazaar.

A marvel of Byzantine engineering under the streets of Istanbul.

A vast Communist-era exhibition space in the Bulgarian capital.

Eastern Bloc nostalgia, anybody?

A reconstructed medieval gateway that was the magnificent entrance to the capital city dating back to 1037.

340-foot statue built to honour the Heroes of the Soviet Union.

This unassuming museum's slogan translates to “there is a limit of sadness, anxiety has no limits."

A surreal museum of extraordinary industrial objects.

A brush maker used his factory to protect blind Jews from the Gestapo.

A restaurant and observation deck built in a unique broadcasting antenna.

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

Where once there was a train station bathroom, there is now this German burger joint.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

A collection of abandoned typographic signs from Berlin and beyond.

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

This classic restaurant features a gorgeous mirror-clad room.

A slice of central Asia in the middle of Berlin.

Fall down the rabbit hole into a surreal journey of human consciousness "from ass to soul."

A whimsical and twisted animatronic monster tour beneath the streets of Berlin.

The pioneer of psychoanalysis spent the final year of his life here, still seeing patients on that famous couch.

The last remaining example of the boatmen's perches that once dotted the south bank of the Thames.

The first tunnel to be dug beneath a river, repurposed as an art and museum space.