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

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

Live a night as a Byzantine King, with a minibar and private jacuzzi.

While not Turkey's deepest underground city, this subterranean redoubt is the largest.

The deepest underground city in Turkey was designed to protect 20,000 people behind massive stone doors.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

A modernist landscape of water and sci-fi concrete.

Home to the largest urban bat colony in North America, estimated at 1.5 million bats.

Tracks near this Texas nature site were once thought to support the Creationist belief that man and dino coexisted.

A Serbian church lit by chandeliers made of weapons.

A towering spire in the fortress of Kalemegdan honors the victorious armies of Serbia during their struggles against the Ottoman Empire.

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

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.

This bridge was constructed from the rubble of the infamous Bastille.

This life-size replica of the Statue of Liberty's flame is also a tribute to Princess Diana by default.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

France's most famous cemetery, with some of its most curious tombs.

How did a French journalist’s grave become the sexiest statue in the cemetery?

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

A majestic lion statue guards this Parisian botanical garden, and feeds on an unsettling item.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

France's national museum of scientific and industrial instruments.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

The celebrated eyesore created by starry-eyed sweethearts.