This beautiful starry sky is a cave full of glowworms in New Zealand

NASA's Astronomy Picture of the Day features an amazing photo by Phill Round. It looks like a frame from a Spielberg movie—an humanoid figure appearing at the base of a mountain, with the unknown starry sky of an alien world behind it. In reality, it's a man getting into New Zealand's Hollow Hill Cave. » 8/30/14 10:20am 8/30/14 10:20am

The complete map to Earth's deepest cave—7,208 feet deep, 8 miles long

At 2,197 meters (7,208 feet) the Krubera cave is the deepest on Earth. Located in the Arabika Massif, of the Western Caucasus in Abkhazia, Georgia, it extends for 13.432 kilometers (8,346 miles.) I would love to get inside, but I know the fear would paralyze me. I love to go through its complete (so far) map, though. » 3/28/14 2:57am 3/28/14 2:57am

The Castle of Shadows, a 15th Century Virtual Reality Room

In 1420, Venetian engineer Giovanni Fontana proposed an elaborate mechanical room he dubbed the Castellum Umbrarum, or "castle of shadows." Sound awesome? It is. In a recent paper, French professor Philippe Codognet described it as "a room with walls made of folded translucent parchments lighted from behind, creating… » 2/22/11 3:20pm 2/22/11 3:20pm

UCSD's StarCAVE Is a Real 3D Super-High-Def Danger Room

UC at San Diego has the closest thing to an X-Men-style Danger Room in its new StarCAVE, a small room that entirely surrounds you, hurtling 68 million pixels at your eyeballs at near-perfect resolution. Pop on polarized glasses and the whole thing goes 3D. Grasping a wireless "wand," you can walk through tall… » 9/19/08 6:00pm 9/19/08 6:00pm