An unfinished tomb carved into a giant boulder in the Arabian Desert.

The remains of diamond fever taken over by the desert.

In Portugal, a secluded stretch of untouched natural beauty hides at the bottom of a steep hill.

Now famous as the "Harry Potter bridge," this impressive concrete viaduct has long been an icon in its own right.

Village of slate houses, built on a white marble outcrop.

Camels and crocodiles share the black waters of this stunning Saharan oasis.

One of the most accessible undersea plane wrecks in the world.

In paradise, feral pigs have claimed an island all to themselves.

An eerie, derelict amusement park in Berlin.

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

“You better take care of me Lord, if you don't you're gonna have me on your hands.” ― Hunter S. Thompson, Fear and Loathing in Las Vegas.

A walk through the historic city center, under the streets of Seattle.

This massive library holds what was once the largest book collection in the world.

This beautiful natural train tunnel is said to grant the wishes of visiting lovebirds.

This Arab fortress was once the largest citadel in Western Europe.

A breathtaking canyon offers stunning views and frightful pathways through an ecological paradise.

This stunning French estate was so lavish that it landed its original owner in jail for the rest of his life.

The bluer than blue waters in these natural Israeli caves are reached via the world's steepest cable car.

The field of tiny caves that mark this Chinese cliffside are each their own historic Buddhist temple.

A monument to the defenders of the Arctic in Murmansk, Russia.

The world's tallest statue of a woman wields the world's tallest sword and is at risk of toppling over.

One of the largest barracks of the Austro-Hungarian monarchy's military is now an abandoned ruin.

The largest treasure hoard in Europe is contained in a castle that was bombed out during World War II.