They call this long foot bridge a swinging bridge, but really it's the bouncing you have to watch out for.

The statues commemorate the legendary mass killing of escaped circus monkeys.

Scattered around Atlanta are little doors with big charm.

This "Plant Farm Museum" is home to the divinely inspired and visionary outsider artwork of Reverend Howard Finster.

This woodland architectural installation acts as a camera obscura for the heavens.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Half of a waterfall goes into the river while the other half seems to disappear.

An earthwork sculpture built by Robert Smithson in the Great Salt Lake only reemerges during drought.

The famed architect designed this Minnesota gas station of the future with a lookout tower.

A half-mile long and three stories high, this bridge over the Des Moines River Valley mimics a descent into a mine shaft.

This open air cathedral invites all faiths to worship under the only roof big enough to fit them all: the sky.

Symbolic attempt to overcome the issues of life.

Erosion and time have created a naturally-formed water park.

Read a book next to a Midtown waterfall.

A mysterious light in the wood, rumoured to be the the ghost of a railroad brakeman.

This freshwater spring fills with 10,000 gallons of water per minute.

The remains of a Rockefeller's lush Italianate estate hidden in the underbrush on the coast of Lake Michigan.

Tour the luxe "glass cage" that inspired and unnerved the architecture world upon its debut.

A tribute to the twin ideals of religion and patriotism, built by a Catholic priest from rocks, glass, and innumerable found items.

For just a few bucks, this Iowa funicular will let you feel like an 1800s fat cat.

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

A collection of relics from the Spiritualist Camp Chesterfield.