Former hotel turned into haunted playground.

This lakefront cottage was crafted in the 1800s and was once a sanitorium.

A circus of light and sound forms a sensory ode to an iconic train that will never pass through town again.

A giant, Gilded Age mansion that once belonged to the beer baron of Milwaukee.

An off-the-beaten-path place to literally hang beneath Milwaukee's Holton Street Bridge.

North Carolina's finest examples of Native American pictographs have survived for 5,000 years.

The land is full of geologic eye candy, such as otherworldly spires, mushroom-shaped hoodoos, and prehistoric fossils.

A notorious Route 66 eatery once frequented by Al Capone.

An abandoned meat mecca now serves as an excellent locale for urban exploration.

This elaborate Hindu temple is located in a Chicago suburb, but looks like it was transported directly from India.

Arguably the best example of an authentic Dutch windmill in the United States, rivaling its counterparts in the Netherlands.

World's second largest particle accelerator, where nature reveals its secrets.

This morbid, delightful curiosity shop offers everything from animal bones to human teeth.

A devastated ruin in the south of Belize where British explorers claimed to unearth the Mitchell-Hedges Crystal Skull.

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

A massive underwater sinkhole made famous by Jacques Cousteau.

Devilish landscape, once cinema home to giant alien bugs, now derelict roadside attraction.

These curious caverns have been home to mushrooms, gangsters, and disco.

The highest point in South Dakota contains the ashes of Valentine McGillycuudy, the "Holy White Man."

Despite repeated attempts to make it work, this former mining town is now nothing but dust and memories.