Rare recess caves fill this unbelievably beautiful Ohio park.

This quirky curiosity shop takes its cues from the world's bazaars.

Crammed into a Baltimore row house is an oddities shop that sells everything from skulls to dead insects.

A museum dedicated to the alleged Roswell Incident.

The eerie remnants of an ancient forest were hidden under the sand for centuries.

Welcome to old Florida, where a 1940s mermaid show is still enchanting visitors.

The magic's in the hole!

The largest earthwork effigy in the world.

According to one local tradition, the entrance to the Voodoo underworld can be found in New Orleans through seven gates scattered throughout the city's French Quarter.

San Francisco's newly reopened hands-on science museum.

This maze-like slot canyon is a unique gem within an already fascinating geological area.

The scuba diving training facility was named for the steam that rises from the cave's chimney.

This strange seaside tower got its name from a wealthy eccentric who would hide coins among its stones.

A "gravitational anomaly" located in the redwood forests just outside of Santa Cruz, California.

This symbolic piece of New Orleans architecture is also home to a few ghastly stories.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

Nikola Tesla's former home contains an homage hidden from plain sight.

New York City's smallest piece of private property.

Hundreds of glow-in-the-dark objects light up a museum in a historic zinc mine.

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

One of the world's oldest and most massive living organisms is a grove of quaking aspens.

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

Odd outsider art installations surround a Gold Rush-era ghost town.

An acoustic anomaly with a mysterious cause.