This raised bulls-eye visible from space was the subject of an intense geologic controversy.

Adobe ruins punctuate the beauty of an 800 foot canyon carved by the Canadian River.

This desert oddity hides in plain sight thanks to a cartographic error and a desert explorer with a punny sense of humor.

Machinery left over from California's once thriving mercury industry now attracts artists and explorers.

One-layer pyramid in Indiana.

Submerged lava formations create incredible waterworks.

This scenic Maryland park was the site of one of the worst prison camps of the Civil War.

A grandiose title could not save this mercantile community from obscurity.

American bison herd descending directly from a Bronx Zoo breeding program that saved the species from extinction.

A petroglyph map of the upper Snake River carved by prehistoric hunter-gatherers.

This botanical garden outside Chicago boasts an array of more than 300 varieties of lilacs.

A watering hole where the options for seating include a bar, patio, or subterranean cave.

Hut with supplies for shipwreck survivors.

Visitors to this arboretum are greeted by three smiling giants crafted from sustainable materials.

Toss a Frisbee through the ruins of this Colorado gold mining town.

The remains of one of the last mining camps developed on the New River.

The graffiti-covered ruins of an abandoned trading post in the middle of the Navajo Nation.

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

Several times a year, during low tide, two pairs of historic train tracks are revealed on this New Jersey beach.

Underground vaults of a former brewery beneath Brooklyn's Crown Heights are now used to ripen cheese.

An ever-evolving wall of graffiti art off East Liberty Street.

This abandoned 19th century orphanage started as a boarding school for children of Civil War veterans.

Industrial ruin decimated this tiny New England company town in a fashion no one saw coming… and even fewer remember today.

Arguably the best example of an authentic Dutch windmill in the United States, rivaling its counterparts in the Netherlands.