Philadelphia boasts one of the best — and most often overlooked — traditional Japanese gardens in North America.

An acoustic anomaly with a mysterious cause.

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

Oh, just a motel on the edge of the desert decorated with thousands of clowns conveniently located next to an abandoned graveyard.

A mysterious castle built as a monument to lost love.

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

The one-stop shop for all of your superhero (or evil arch-nemesis) needs.

A modernist landscape of water and sci-fi concrete.

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

Take a drunken tour inside the world's largest known geode.

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

A tunnel once abandoned now thrives with graffiti art as an off-limits makeshift gallery.

A breathtaking array of ancient Pueblo structures and artifacts counterintuitively preserved by neglect.

The abandoned husk of a mental institution that failed to save a Jazz Age icon still sits nearly unchanged.

A beautiful 62-acre Catholic shrine and botanical garden.

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

The oldest surviving bridge in New York City, which reopened to pedestrians in 2015.

The remains of a failed attempt at medieval nerdery are hidden deep in the woods of Virginia.

More gold than anywhere else, ever.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

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

An abandoned castle owned and ignored by Masons carries a cursed history.

An underwater city for the dead.

This unique structure in suburban Austin is made up entirely of other people's castaways, and constantly changing.