New Orleans' famous cemetery, located on the site of a former race track.

The loneliest island in New York.

Read between the lines of the subway map to find the hidden abandoned Civil War fort.

America's only nuclear missile silo open to the public.

This geothermal hot spring hides beneath a slowly growing mineral dome.

A beautiful 62-acre Catholic shrine and botanical garden.

Treehouse motel and treehouse-building school.

Moonbows over Kentucky.

A clear blue swimming hole with hidden caves, still unexplored.

A Museum of Holography frozen in 1974.

Remember that scene in the Matrix, when Neo is in the big white room with all the weapons flying by? Well, this is what it would look like if he had wanted trees instead of guns.

This frequently-photographed waterfall takes only a short hike to visit.

A late sculptor's last project was to turn this abandoned cement factory into a castle-themed amusement park.

This rugged area of red rocks and arches is often considered one of the most beautiful places on Earth.

Oregon's unexpected high desert, displaying layers of time in a colorful show.

James Turrell's total color immersion art installation, hidden on the top floor of a luxury handbag shop.

It's not hard to see why the historic Peabody Conservatory of Music's library has been described as a "cathedral of books."

The largest self-built castle in the U.S., six decades in the making.

A piece of outsider public art accompanied by a strange urban legend.

Bizarre lunar-like landscape with thousands of large stone "hoodoos."

In the remote high desert of New Mexico, a strange array of poles beckon fury from above.

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

A popular swimming hole that hides one of America's most deadly diving spots.

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