The preamble to the U.S. Constitution written entirely from vanity license plates hangs in the Smithsonian museum.

The entire length of the border is marked by a 20-foot-wide slash through the trees.

Prehistoric history as seen through the lens of an outsider artist.

Reaching the "Church in the Sky" requires scaling the cliff face of a sandstone pinnacle with a 650-foot drop.

This narrow coastline trail through the dense Kauai wilderness is among the most beautiful and dangerous in the world.

Founded as a refugee camp, now a popular tourist spot.

This hulking behemoth is actually five interconnected towers built in the 1960s.

The sculpture is made of more than 100,000 knives collected to raise awareness about violence.

A rainbow-colored house promotes LGBTQ rights across the street from the Westboro Baptist Church.

A chain of bells connect the California Missions and honor the legend of the "King’s Highway."

A working model of the entire San Francisco Bay and much of the Sacramento River Delta, complete with regular tides that change every 14 minutes.

A dwindling menagerie of anthropomorphic oil derrick animals still dot the barren California landscape.

A small chapel celebrating the spiritual bond between dogs and humans.

Morocco's Argania trees are infested with nut-hungry goats.

This bridge is so steep it looks like a rollercoaster.

One of the largest, oldest, darkest, quietest motel rooms in the world.

A valley of unique erosion patterns lends to a view like nothing on Earth.

Gambling, boozing, and yodeling animals cover the walls of this dive bar cum natural history museum.

Unique geological formations in China, featuring some suggestive shapes.

America's most famous piece of self-built architecture.

This neon blue river gets its color from a unique mix of bacteria and volcano minerals.

This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

At nearly 1,000 feet long, this astonishing glass suspension bridge is one of the longest in the world.

A Hawaiian stairway to heaven—that you can't climb.