A precariously balanced rock perches on the edge of a cliff created tens of thousands of years ago by glacial erosion.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

Dramatic river bend surrounds a natural red-rocked pedestal.

Rippling sand dunes frozen in the Arizona rock.

Giant pinnacles in the sun-scorched lands of Southern Utah have been nicknamed "white ghosts."

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

This quiet park's strange sedimentary spires were named after Kodak's color film.

Local lore holds that Butch Cassidy took an escape route through Red Canyon's sandstone hoodoos after an attempted murder.

Settled by the Church of Jesus Christ of Latter-day Saints in 1859, this abandoned frontier town has appeared in several films.

Hundreds of drawings left by the land's previous inhabitants remain mysterious.

A Norwegian-born sculptor created these soaring guardian angels at the entrance to Hoover Dam.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

An atomic bomb-proof strongbox protects the U.S. Constitution from terrorists and thieves.

Members of Congress have traveled between the buildings on Capitol Hill for a century hidden from tourists, press, and storm clouds.

Enormous piles of historically significant stones, dumped by Congress in a forest, and abandoned for 60 years.

Look closely and you’ll notice that the color changes a third of the way up the tower.

The monument's pointy aluminum tip has been melted down by repeated lightning strikes.

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

The lecture hall where Alexander Graham Bell first demonstrated the long-distance phone call.

Experience the hysteria of a 17th century witch hunt through goofy reenactments and wax dummies that should probably be burned at the stake.

The only structure left with direct ties to the Salem witchcraft trials of 1692.

A charming museum of natural history featuring dioramas and exhibits made entirely by college students.

On a former island, this old fortification once used to protect the Boston Area and started Edgar Allan Poe in his military career.

A former waterfront market is now in the center of town due to some interesting Boston engineering.