Opulent downtown movie theater now houses cars as an indoor parking garage.

38-story baroque tower reflecting Detroit's rise, fall, and possible rise again.

This railway-turned-greenway provides a pedestrian link in downtown Detroit and celebrates urban artwork.

This 1960s kinetic artwork has been restored and is once again whirling away in downtown Minneapolis.

A whimsical sensor instrument for Minneapolitans to play on their walks to work.

An old town theater converted into a celebration of the hobo legacy.

This geodesic gallery holds a collection of painted spheres that make traditional canvases look lazy by comparison.

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

One of America’s oldest and spookiest hotels, thanks to the residency of ghosts, dead presidents, and Alfred Hitchcock.

Every president in history is immortalized in bronze in downtown Rapid City.

One of America's first dinosaur parks gives a window into Depression-era paleontology.

A waterfall 600 ft. inside a mountain, once the bane of gold miners, is now a spectacle of nature.

A place where the laws of nature seem to have gone completely berserk... but of course haven't.

Hidden behind Lincoln's head is a 70-foot-long chamber containing enamel plates documenting American history, sealed in a teakwood box in a titanium vault.

The highest point in South Dakota contains the ashes of Valentine McGillycuudy, the "Holy White Man."

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

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

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

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

The winding route passes through an enclosed alleyway, two tunnels, and leads to the White House basement.

A Civil War fort in the middle of Washington, D.C. has been swallowed by a forest.

A nostalgic bibliographic gem.

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

The country's oldest continually-operated mini golf course lies hidden in plain sight, eclipsed by one of D.C.'s most popular tourist attractions.