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

A museum dedicated to the history and exploration of both popular music and science fiction.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

A walk through the historic city center, under the streets of Seattle.

The rocks in this arid basin leave trails of movement behind them.

The ghostly remains of an accidental sea.

An enormous, inside-out glass globe built in 1935.

World's first "penitentiary," meant to be humane, drove men insane.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

The official atomic museum of the United States explores the explosive and productive history of a much maligned energy source.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

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

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.

A reproduction of earth's many biomes.

An urban laboratory.

The largest natural travertine bridge in the world is nestled in a small canyon in central Arizona.

The massive, incredibly rare instrument is over 11 feet tall with a range so deep it goes lower than humans can hear.

This striking public art installation is suspended above a public park, designed to gently move in the breeze.

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

These free-roaming horses were once destined to disappear from the land.

Scores of vintage street lamps shine along L.A.’s Miracle Mile.

Historic funicular railway, believed to be the shortest railroad in the world.