An acoustic anomaly with a mysterious cause.

Beyond being incredibly fun, not much can be said about the Hole with certitude.

George Washington's dentures and Queen Victoria's dental instruments are in the nation’s official museum of the dental profession.

This museum boasts a bucket of teeth and tells the tale of a 20th-century dental circus.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

This unique Renaissance castle was turned into a home for Nazi occultism.

World War II-era Nazi compound nestled in the Santa Monica hills.

The prototype for all Nazi concentration camps.

An eerie, derelict amusement park in Berlin.

Remnants of a storybook amusement park hidden behind a strip mall.

A theme park that suffered massive flooding during Katrina was abandoned, and now proves irresistible to trespassing explorers.

This attraction was abandoned after the Chernobyl disaster.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

The beauty of urban decay, hiding some dark secrets.

Terrifying derelict military hospital once housed a recuperating Hitler.

The abandoned zoo enclosures offer a perfect place to experience the other side of the bars.

The ghost town left by the worst nuclear disaster of all time is being taken over by nature and urban explorers.

The macabre paintings created by famous suicide proponent Jack Kevorkian, or "Dr. Death."