The sign at the garden gate reads: "These Plants Can Kill."

The vast, legendary catacombs hold secrets much stranger than stacked bones.

A church of bones, decorated with 40,000 human skeletons.

The birthplace of America's favorite fruit-flavored mystery dessert.

An abandoned castle owned and ignored by Masons carries a cursed history.

America's greatest forgotten garden and the former stomping grounds of Son of Sam.

A tourist attraction founded around a slumping cabin.

A volcanic fissure over two miles long and up to 70 feet deep.

China's mysterious record-setting sleeping Buddha.

Ancient man-made caves underneath small town Belgium.

A metal tree emits eerie, melodic notes on top of Lancashire's Crown Point.

This small primate research island is teeming with playing, fighting wild monkeys.

A dangling church built over a Colombian gorge.

A submerged village appears when dam levels drop.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

The world's toughest modern Christian pilgrimage leads directly to the gates of Hell.

Ruins of a 10th century church tucked away deep in a botanical garden.

Abandoned railway line circling the city of Paris.

Walk over a 150 year old manhole.

Island, once a pirate hideout, now home to an abandoned resort.

A Turkish ghost town abandoned in a population exchange with Greece.

The fantastic architectural models of a French traveler.

This French ghost town from World War II has been left as a memorial to German atrocities during World War II.

Ancient paintings known as the "Sistine Chapel of Cave Art."