Breathtakingly blue walls shimmer inside the "Glacier Behind the Town."

A swing to dangle you off the very edge.

Partially collapsed lava tube and cave system complete with concert hall, underground pond, and unique albino crabs.

Stroll through a wonderland of stupendous moss-covered trees.

Stalactites and stalagmites in a beautifully lit cave.

Odd outsider art installations surround a Gold Rush-era ghost town.

These mammoth-yet-narrow crevasses in the Earth are perfect for taking an otherworldly swim.

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

A Museum of Holography frozen in 1974.

The subtle science of a master molecular gastronomist.