Climb a steep hill in 90 seconds on the second-oldest urban subway in the world.

This half-forgotten fortress was constructed by the Ottoman conqueror of Constantinople.

This former Imperial summer home was the venue for a royal slap that once echoed 'round the world.

Over the centuries, this island paradise has done it all, from providing monks with ecclesiastical respite to sheltering an exiled Leon Trotsky.

One of the largest wooden constructions in Europe was meant to be a casino, but soon became an orphanage.

This famous city eluded concrete detection until the early 2000's.

This elevator was built in 1907 to connect two neighborhoods separated by a steep, rocky cliff.

Seven early Christians were sealed into a cave where legend has it they slept unharmed for centuries.

A charming beach town in Turkey captures all the colors of the rainbow.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

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

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

A marvel of Byzantine engineering under the streets of Istanbul.

Macabre astrological automaton clock dating to the late 1400s.