It's believed that this small church was connected to the Hagia Sophia via a secret tunnel.

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

The most metal church of all time was built in record time because of an international, pious pissing contest.

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

One of the newest mosques in a city filled with thousands.

This historic hotel preserves many treasures from its heyday hosting passengers on the Orient Express.

A gorgeous, Gaudí-esque stairway constructed in the city of Istanbul by a prominent Jewish family.

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

A surprising and unconventional mosque hidden in the subsoil of Istanbul.

Taking the subway here means doing so over a bridge located in the middle of an estuary.

A small etching on the white marble parapet was written in runic script by a Viking mercenary.

This crucial gathering spot along the "hippie trail" still displays old notes between traveling beatniks and backpackers.

A marvel of Byzantine engineering under the streets of Istanbul.

Legend says if you stick your thumb in the hole and it gets wet your wish will be granted.

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

The legendary luxury train passage is commemorated with a charming museum inside its former eastern terminus.

An Art Nouveau gem hides beneath the layers of city grime obscuring this once-magnificent building.

Turkish adventurer antiques in the heart of the Grand Bazaar.

A tiny park in the middle of some big power politics.

Ancient serpentine sacrifice holder that has stood the test of time.

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

A fountain standing as a testament to a doomed alliance.

Order a salt beef-loaded beigel at any hour of the day or night at this East End institution.

Come for the oysters, stay for the priceless art honoring inventors across history and Scotland's favorite outdoor sports.