The national park was once a plantation estate.

The walls of the iconic dome are hollow and have a secret stairway.

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

The site of the climactic scene from the classic horror film is now a historic landmark.

Stairs often replace streets on the steep slopes of this old mining town.

An old saloon in the West filled with history, and according to some, a few dozen ghosts.

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

The only road through the heart of Glacier National Park.

This town is home to the world’s largest arch constructed entirely of elk antlers.

This shallow pit was once used to send over 20,000 buffalo plummeting to their death.

This rustic old building is said to be the most photographed barn in America.

This Yellowstone geyser may not shoot as high as the nearby Old Faithful, but it erupts for considerably longer.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

A beautiful geyser under environmental threat.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

The granddaddy of all tourist traps, built on ice water, jackalopes, and a giant dinosaur.

While most wind tunnels test scale models, the "Cave of Winds" was large enough for actual airplanes.

Home to a vast and influential collection of Shakespeareana.

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

Decades before the scandal, this staircase on the river was a literal "water gate."

Perhaps the most scandalous statue of America's first president.

The "lovely red Vega" of the legendary record-settling pilot.