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

An underground network of massive stone arches and their skylit vaults support ruins of portico structures above.

This crumbling medieval basilica once attracted pilgrims by the thousands to collect a miraculous dust that formed above the saint's tomb.

This arch granting triumphal entrance into Antalya was designed to honor the emperor's visit.

A sacred lake with thousands of sacred carp and a biblical history.

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

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

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

The ancient abodes are a testament to human ingenuity amid harsh climates.

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

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

This column celebrates Rome's victory over the Goths, and may be the oldest Roman monument in Istanbul.

The only residents of this abandoned housing development full of identical castles are stray cats and dogs.

A fountain standing as a testament to a doomed alliance.

Roman ruins, natural methane fires and a lovely beach.

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

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

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

Flames have been burning within this mountain for more than 2,500 years.

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

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

This hunter-gatherer architecture is believed to be the oldest religious complex known.

A Lycian city of the dead carved into the hillside of Southern Turkey, complete with startlingly human touches.

A marvel of Byzantine engineering under the streets of Istanbul.