The ruins of an abandoned medieval city where the last Byzantine emperor was crowned.

A quirky bookstore hidden beneath a sea of whitewashed Greek villas.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

A minotaur, a labyrinth, and a dubious restoration pull in visitors from around the world.

Hidden in a secluded Greek cove is a pristine beach marred only by the rusting smuggler's hulk stranded on its shores.

The hallucinogenic center of the ancient world.

Monasteries on rock pillars, once accessible only by frayed ropes.

The vast chamber inside this abandoned cooling tower looks like something out of a sci-fi dystopia.

This historical Netherlands fortress still bears the marks of its single siege.

This sprawling Belgian fort was once thought of as impenetrable but now it is simply an abandoned relic.

A Belgian self-built tower inspired by the Bible and ancient civilizations.

A beautiful maze marks where three countries meet.

Sculpture designed by Turkish artist and professor Mehmet Ali Uysal.

This medieval castle overlooking the Elzbach river looks just like it did hundreds of years ago.

This striking fort on the Maginot Line looks just as it did after being destroyed in the Fall of France.

The highest point in Belgium is a staircase to nowhere.

The remains of 40,000 humans, meticulously stacked in a tiny churchyard shed.

This tri-part waterfall is a little bit of fairytale beauty in the heart of Luxembourg's Little Switzerland.

Climb inside an iron crystal magnified 165 billion times its normal size.

This fairytale castle was built as a show of power but was nearly torn down thanks to its history of torture.

A magical and peaceful ruined Cistercian abbey in what is now southern Belgium.

Walk 2,300 feet above the ground on the "Troll's Tongue."

An Italian hillside ghost town.

Tiring of digging out the door to this church for every service, it was eventually abandoned to the sands.