Many generations of travelers have passed through the steep, smooth walls of this canyon.

This National Natural Landmark is one of the best examples of a “mass wasting” in the world.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

Rare recess caves fill this unbelievably beautiful Ohio park.

Dedicated to the art and science of glass in equal measure, this space is as much laboratory as museum.

The little-known final resting place of one of America's greatest writers.

This 40-room dwelling tucked within a cliff was built by the basin's prehistoric residents.

A small horde of mythical creatures lurk almost imperceptibly within the museum's wildlife dioramas.

Tens of thousands of tiny birds swarm into one school chimney every fall.

A sculpture of a salmon swimming through a brick building.

Stalinist skyscraper built with help of cryotechnology.

Former headquarters of the KGB.

The "Mystery and Company of Merchant Adventurers" is an Elizabethan-era hangout in Moscow.

Formerly secret, precariously perched boulders.

Sunset-colored dunes of volcanic ash make taking a poor photo impossible.

The huge collection of paintings of the American West is one of Denver's best-kept secrets.

The quaint little Vermont town played a quaint little Connecticut town in Tim Burton's "Beetlejuice."

Beautiful hillside Vermont cemetery with amazing funerary art.

Tour the world's largest deep-hole dimension granite quarry, where you can view the plant where gravestones are made and roll a ball down the outdoor granite bowling alley.

An obscure waterfall that looks like something out of a fantasy novel.

Rising out of miles of farmland, these buttes are sometimes called the world's smallest mountain range.

An entire town preserved as a historic landmark.

The scene of one of the darkest moments in American labor history has been left essentially untouched since the tragedy.

A ghost town that held steady longer than most, but finally gave up the ghost.