A tiny red pebble marks what may be the quietest outdoor spot in the United States.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

The first park built over a freeway is a brutalist masterwork.

Possibly the most beautiful carillon in the world, set atop Iron Mountain in Florida.

Ruins of a Carnegie family mansion on Cumberland Island.

A haunted hot springs hotel that went from healing retreat to asylum before it was restored.

Despite a legend that says this highest peak in Oregon was climbed in high heels scores of people have died on its slopes.

Portlandia is the second-largest copper repoussé statue in the United States.

The world's smallest park was dedicated in 1948 as the only colony for leprechauns west of Ireland.

The magic's in the hole!

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

This extravagant Art Nouveau rest stop features a million-dollar view of the Columbia River.

Shoreline strewn with the remains of ghostly fallen trees.

A glimpse into the "Logging Capital of the World" at a time when there was far more forest and far less machinery.

The highest point in Washington state is a volcano covered in glaciers.

City Council meetings still happen in this historic building, impeccably preserved on the inside.

This prehistoric sinkhole lured exclusively male mammoths to their death, much to the delight of science.

These former Cold War launch sites have been preserved for tourists to see where the button might have been pushed.

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

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

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

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

Thanks to a loophole in property ownership, this alleyway has become a cacophonous street gallery.

South Dakota's oldest operating brewery is housed inside a historic firehouse.