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.

A fitting attraction for the corn capital of the world.

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

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

This replica stave church looks like a piece of Norway was simply plopped down in South Dakota.

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

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

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

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.

The ruins of a stone tower with alleged (but unlikely) Roman origins.

This tall stone wall with no door and ill-matched windows was built centuries ago, and used as a shelter for domesticated pigeons.

The castle still holds traces of the abandoned Roman fort it was built atop.

This neolithic stone grave has been altered and restored so often its now more neo than lithic.

This Roman amphitheater is said to be King Arthur's legendary Round Table.

This Welsh village gave itself a ridiculous name in a publicity stunt a century ahead of its time.

The Stonehenge of Wales is one of the grandest neolithic dolmens still in existence.

Hundreds of prehistoric stones, arranged in perfect lines in a French field.

The largest and most well-preserved petroglyph site in the Verde Valley.

Eons ago, a rushing lava river formed this pristine passage through solid rock.

Ancient pueblos built into the base of a natural canyon wall.

A planet-hunting astrograph built in the 1920s to seek out the so-called "Planet X" beyond Uranus.

This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.