The front yard of an Upper East Side town house hides the last fragment of one of New York's most famous theatres.

The former hotel where Tesla invented the radio.

A Manhattan courthouse hides a small but scathing memorial to Holocaust injustice.

The oldest alley in San Francisco is paved with a reminder of the city's original shoreline.

The original place where water met land in the City by the Bay is outlined in brass.

Try not to get slimed in Tribeca.

Architecture lovers won’t stop touching the National Gallery's 19.5 degree marble prow.

The house where John Wilkes Booth conspired with his co-conspirators.

Largest Roman Catholic church in North America.

The first purpose-built art gallery in the United States is once again open as a center of craft arts.

A three-story tower of books about Abraham Lincoln is one of the more unusual monuments to the president.

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

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

Washington's iconic carousel has a nice piece of Civil Rights history.

A self-built castle made by a mysterious man.

Founded by members of the Tohono O’odham Nation, this one-room joint's James Beard–winning fry bread is light as a cloud.

This small, unassuming street is now a canvas for color and creativity.

The installation’s official name, “You Who Are Getting Obliterated in the Dancing Swarm of Fireflies,” says it all.

Legend says train robbers stashed their gold within the depths of this unusual cave.

See massive fossils that are over 200 million years old in northeastern Arizona.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

A spiritual vortex among the red rocks in Sedona.

Take a monster truck tour around an ostrich farm in the middle of the desert.

Some of the tallest ancient American ruins continue to inspire awe and curiosity.