Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

The "world's biggest dinosaur" once housed a creationist museum in its abdomen.

A huge musical sculpture and other art installations on the National Oceanic and Atmospheric Administration grounds.

An acoustic anomaly with a mysterious cause.

Hidden in an ordinary Midtown building is a one-room museum dedicated to the greatest escape artist.

Breathtakingly blue walls shimmer inside the "Glacier Behind the Town."

A modernist landscape of water and sci-fi concrete.

A museum dedicated to the alleged Roswell Incident.

Seemingly grown on some other world, these New Mexico rock formations look like a disused science fiction set.

One of only two commuter aerial tramways in the United States.

New York City's smallest piece of private property.

This little museum is built on a theater that was once a wildly elaborate speakeasy.

A beautiful Victorian-era cemetery, complete with a miniature village.

A strange house built only at night, with rumored mystic inspiration.

Towering basalt columns, a creation of fire and ice.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

A walk through the historic city center, under the streets of Seattle.

The unique waterfall in Iceland's south features a backdrop of geometric black lava columns.

A collision of human error and natural geothermal pressure created this rainbow-colored geologic wonder.

Tucked in the back of this amazing antique store is an important piece of medical history.

This unique crypt designed by Frank Lloyd Wright for his longtime friend was not completed in either man's lifetime.

This mill on Lake Erie appears to shrink as a viewer approaches thanks to an optical illusion.

This "Palace of Purification" has made many film appearances as a dark and sinister headquarters.

A school teacher's massive and terrifying self-built castle.