This Catskills museum preserves stumps from the earliest known fossil forest on Earth.

Why have you never heard of the second most popular tourist site in New York?

Fossilized sea bottom and lime quarry.

This petite park lets visitors see and touch examples of fossilized dinosaur tracks.

A small museum packed with specimens from important fossil sites and minerals from historical pegmatite quarries.

Naturally formed white marble arch housed in an abandoned marble quarry from the 1800s.

This Roman quarry once held secret masses and smuggler's contraband and is now home to rare species of bats.

Reforestation in action is the main attraction in this abandoned quarry.

The quarry was abandoned over 100 years ago, after a massive ammunition explosion ended in tragedy.

This ruined quarry once produced the distinctive red sandstone used for construction projects in Washington, D.C.

Hiding behind a grocery store is a spectacular cavern carved as part of an old limestone quarry.

Locals purchased this abandoned quarry in order to make sure it continues to be overgrown.

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.

Patrick Dougherty's fantastic living tree sculptures, mind-blowing but temporary.

The only remnant of a small mining town is an abandoned railroad tunnel that is steeped in ghostly lore.

An abandoned theme park with a strange and tumultuous past.

Rare recess caves fill this unbelievably beautiful Ohio park.

The home used in just a few seconds of film that came to define the setting of a hit sitcom.

The world's longest known cave system.

This grave in a ghost town cemetery marks the death of a witch on a day that never happened.

See the nearly two-century-old ruins of pre-railroad America at the former site of a lock on the Ohio and Erie Canal.

Beautiful waterfalls grace a canyon visibly torn by a violent tornado.

The entrance to this sinisterly named tunnel hides behind a Tim Hortons.

This former Indiana quarry has been transformed into a park and SCUBA site where divers can explore the drowned mining equipment.