The longest continuous lava tube in the continental U.S. offers 2.5 miles of dark explorations for the adventurous.

Hollowed out cedar log tubs set in an ancient towering forest.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

Beyond being incredibly fun, not much can be said about the Hole with certitude.

These old stone ruins in the Oregon wilderness were once bathrooms and are steeped in legends of murder.

An emporium for the weird, creepy, rare, and just plain gross.

The artist James Turrell is repurposing an extinct volcano crater as an observatory to experience the cosmos.

An abandoned facility that has become a place of ritualistic satanic worship, or so rumor has it.

An homage to everyone's favorite prehistoric cartoon family.

A reproduction of earth's many biomes.

One of the world's largest telescopes, stares into the night sky with two huge mirrors.

Limestone caves with spectacular showcase chambers.

An urban laboratory.