A mysterious spot where the laws of gravity seem not to apply.

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

This tall Massachusetts folly got its name thanks to all of the purple prose its vistas inspired.

Over fifty whirling pools left by the glacial age.

The bridge's highly-contested plaque (once again) honors Confederate President Jefferson Davis.

This Connecticut chapel is a starkly modern, and surprisingly colorful, architectural rebel.

This stretch of beach along California's central coast is a busy highway for the largest seal in the northern hemisphere.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

The corpse bride of Portugal.

Housed in a memorial lighthouse, this museum relays the history of surfing, beginning with the antics of royal Hawaiian teenagers.

The medieval castle built as headquarters for the Pope's secretive Knights Templar.

Burping, gurgling geothermal mud pots by the Salton Sea.

The splendor of this 17th century golden chapel has led it to be called the "eighth wonder of the world."

Haven for steampunks.

The highest point on the island known for buildings that touch the sky.

Erected in 1697 this Philadelphia bridge is the oldest surviving roadway bridge and perhaps the oldest stone bridge in the United States.

This elaborate towering structure was once famed for its revolutionary height.

The highest point in Delaware is located under a trailer so this marker across the street will have to do.

An Aztec temple, the largest man-made pyramid in the world, sits buried in earth with a Spanish church set on top.

The only home that Alexander Hamilton ever owned has a history almost as troubled as his own.

Twenty-seven massive radio antennas on the high plains of New Mexico search for life on other planets.

A one-of-a-kind sundial at the Very Large Array honors a radio astronomy pioneer, incorporating the original piers from his breakthrough radio telescope.

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

Even Henry David Thoreau found this glacial pothole irresistible.