The John Snow Memorial marks the epicenter of London's 1854 cholera epidemic.

The world's first underground farm is in a World War II bomb shelter beneath the streets of London.

The highest dunes in California are the most likely place in the area to hear the Singing Sands.

World's oldest operating science fiction and fantasy club, once home to Ray Bradbury and L. Ron Hubbard.

An institution that preserves the history of institutionalization.

An incarceration museum on the spot of possibly the oldest prison in England.

Tour the sci-fi-esque reality of governmental disease management.

The one-time stronghold of the noble Douglas family, now home to ghost sightings and nesting birds.

Gutted airplanes slowly decay in a Florida field.

No one knows how this Pacific Northwest spruce tree came to have so many trunks.

The haunting ruins of Jack London's dream house.

The history of radiation is on safe display at the foot of a radiation science laboratory.

The location of the last stand of Charles Manson's doomsday cult.

The remnants of two World's Fairs are here, complete with a 12-story globe, a mini-Manhattan, and a UFO-shaped pavilion.

A 18th century graveyard and its astonishing cortege of macabre iconography.

The oldest family-run luncheonette in New York, last renovated in 1948, still serves food and drinks the old-fashioned way.

A secretive collection featuring objects that were designed specifically for U.S. intelligence operations.

Stroll the grounds built by murder, suicide, and dirty oil money at one of Hollywood's most filmed mansions.

Acres of natural wonders left behind by a socialite-turned-gardener.

The ruins of the castle that chemicals built.

A popular tourist cave with a dark past.

A collection dedicated to the treatment of disease, held in London's oldest hospital.

Indents in the pavement are all that remain from a grisly death machine in Paris.

The decaying ruins of Wales' first asylum for the mentally ill.