These homes carved into the mountains seem to defy the laws of nature.

The history of the traveling carnival is remembered by this sprawling collection of vintage wagons, games, and rides.

These historic buildings once housed the headquarters of one of the most infamous gangs of New York.

One of the last Jazz Age "Wonder Theaters" in New York City.

Walk over a 150 year old manhole.

This semi-hidden Manhattan restaurant is based out of a loading dock.

This picturesque abandoned home is rumored to be a spite house.

Sparkling, calcite-covered skeletons of children who may have been sacrificed to appease an angry god.

Hidden deep in the Guatemalan jungle is a turquoise paradise of natural pools, caves, and waterfalls.

One home in the historic strip hides secret compartments and the ghostly songs of long-gone canaries.

An archive of ceramic eggs painted to record clowns' personal makeup designs.

An Oxford museum where visitors can have tea with the Mad Hatter and climb through the wardrobe to a fantasy land.

A collection of beautiful crystals shaped like freshly plucked roses.

This remote British Imperial telegraph relay outpost drove men insane.

Nature's water park in the Wadi Bani Awf valley is full of pools flanked with cliffs and natural water slides.

This giant underground cave chamber can only be accessed through a small opening at the top.

This bazaar is one of the oldest in the Arabian world.

Groups of prehistoric tombs that dot the mountains of northern Oman.

A sinkhole and now a swimming hole, too, full of dazzling turquoise water.

An imposing Omani fortress surrounded by date palm trees.

A 20th-century picture show in 3-D.

This unique railroad museum secretly contains the history of Poland rebuilding itself from the inside-out.

The shattered remains of the world's once tallest structure.

The abandoned husk of a mental institution that failed to save a Jazz Age icon still sits nearly unchanged.