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

A subterranean Holocaust refuge within one of the world's longest cave systems.

Travelers exchange letters with woodland creatures at this mini post office.

This domed temple was built in a hidden cave mouth as a refuge for sinners seeking absolution.

The remains of a Canadian train crash are now mouldering beneath layers of rust and graffiti.

This haunting stone chasm is a hotbed of mossy rock and English legend.

This secret Swiss fortress is disguised as a harmless pink house, complete with fake windows.

The oldest (maybe) swimming pool in Iceland is a stunning oasis built into the side of a lush hill.

The lush coastal city of Astoria is riddled with forgotten secret sidewalks.

One of the world's steepest streets seems to have houses sliding down it.

The second-longest continuous wall on the planet protects a hidden secret in the deserts of India.

This complex of vertically-excavated Buddhist, Jain, and Hindu monolithic temples in India's Maharashtra providence illustrates a spirit of tolerance characteristic of ancient India.

Rock-cut cave complex filled with ancient Buddhist artwork.

Museum preserving torture methods from the past.

A grassy pyramid named after a French battle.

A tunnel dug through the side of a mountain by hand provides convenient yet death-defying access to a small village in China.

The Twisted Trees of Alticane are an unnerving grove of Quaking Aspen, apparently mutated from a single source, giving them a twisted and unnatural appearance.

A Mayan village preserved for centuries in volcanic ash.

Morocco's Argania trees are infested with nut-hungry goats.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

The bullet-riddled wall from the St. Valentine's Day Massacre, bloodstains enhanced for your viewing pleasure.

This museum preserves the hand-dug tunnel that kept Sarajevo afloat during the Serbian siege.