The longest continuous lava tube in Oregon.

This Transylvania County city is home to a rare white squirrel population that is descended from an escaped carnival animal.

The world's widest single drop waterfall, and the two men who legend says went over its edge in a boat.

This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

World's only nuclear reactor operated by liberal arts undergraduates.

Remember that scene in the Matrix, when Neo is in the big white room with all the weapons flying by? Well, this is what it would look like if he had wanted trees instead of guns.

A stunning landscape of bunkers that once stored chemical weapons.

A sacred lake composed of over 300 separate pools of highly concentrated minerals.

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

A home made entirely from scrapped, reclaimed and recycled material in Whitman County, Washington.

This historic Idaho island is home to a strange timeshare museum, a homemade mini-golf course, and an outhouse named Aunt Fanny.

Sandstone rock formations that look like they belong on the cover of a progressive rock album.

The superstar of Cold War nuclear bunkers has been featured in countless films but is now barely operational.

Silver in the hills led to the speedy creation of this boom town and a lack of it saw the town abandoned nearly as quickly.

At the tallest peak in Colorado, an electrifying mix of thin air, lightning, and rivalry.

These aggressively sustainable art homes look like something out of 1970's science fiction.

The childhood home of Henry Jones Jr. is now an adventure-themed bed and breakfast.

A fake mine that was made using real mining techniques which is also used as a community center.

An emerald-green grotto just a short trip from Austin.

A humid oasis combines recreation with exploration in a unique underwater cavern.

A spectacular cave and a beguiling lake.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

A walk through the historic city center, under the streets of Seattle.

This semi-secret garden in south Seattle emulates a traditional Japanese garden using the plants of the Pacific Northwest.