Quite simply the largest tree in the world (by volume).

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 geothermal hot spring hides beneath a slowly growing mineral dome.

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

An outdoor sculpture park of giant pink robots and post-apocalyptic Christmas scenes.

A former Oz-themed attraction that has fallen into disrepair, but still holds some of the original magic.

A bizarre roadside attraction and the first instance of miniature golf in the world.

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

The haunting, dilapidated remains of a former poorhouse on Staten Island's Greenbelt.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

Rustic natural hot springs in the deciduous rain forest.

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

A castle built by an eccentric medieval enthusiast in rural Ohio.

Eons old volcanic activity created one of the most stunning rock formations in the United States.

This charmingly homemade amusement park has been growing for 40 years.

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

A self-built castle made by a mysterious man.

Canyon walls shrouded in ferns.

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

The ghost town that ended up on Ebay.

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

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

Just a few miles from downtown Atlanta is a trail covered in a crazy collection of outsider art.

Abandoned bridge hidden deep in the San Gabriel Mountains.