The world's largest man-made underground caverns offer unparalleled underwater wonders.

Erosion and time have created a naturally-formed water park.

In the St. Francois Mountains in the Ozarks at 1,772 feet above sea level, Taum Sauk Mountain is the highest (and possibly oldest) peak in Missouri.

Once an ambitious nature spa, these forest ruins now provide a serene monument to failure.

If there's another drive-through golf-cart bar in a bat-filled cave on top of a mountain, we don't know about it.

This charming woodland trail is peppered with poetry.

An ancient glacial pothole waterfall in the heart of the Green Mountains.

Driftwood dinosaurs lurk within trees covered in a rainbow array of avian abodes.

This unusual building straddles two countries.

The remains of a deserted 1800s farming community can be found in Little River State Park.

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

The highest peak in the state of Vermont has some interesting features.

This New England covered bridge is home to the tale of a jilted lover known to haunt the area.

This cavernous abandoned marble mine is popular with ice skaters in the winter.

The "original web site," this farm in Northern Vermont encourages orb-weaver spiders to build their daily webs, and then sells the preserved masterpieces.

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.

This New England drive-in was built to straddle the border between two states.

Known as one of the most climbed mountains in the world, this barren peak is permanently bald thanks to an anti-wolf fire.

This 150 foot seven-tiered cascading waterfall is one of the hidden gems of the White Mountains.

This Art Deco theater is the last remaining opera house in the “little Broadway of the North.”

This candy-striped tower is the farthest east you can go in the United States.

Walk the same tracks that once ferried Gilded Age aristocrats to their vacation destinations.

Steam engines and conveyor belts are remnants of a genius system left in the middle of the Maine woods.

The largest tidal whirlpool in the Western Hemisphere.