Located near Angels Camp, California, the Moaning Cavern is a huge solutional cave, (one of the largest in the US), with its first champer measuring 100 feet across and 165 feet deep. It's an impressive cavern to visit, and I strongly recommend you seek it out.
This limestone cavern near Angels Camp is the largest natural limestone cavern in the US. It's very impressive, and pictures cannot give you a sense of scale. Or rather, cannot make you feel like you lost that sense entirely.
That's a 100 foot winding staircase.
Showing off several limestone formations in "one" formation
You lose all sense of perspect inside the cavern. This formation is something like 22 feet high.
Also I'm pretty sure this is Cthulhu, although the calcite's probably made it too much effort to bother moving for small fry like tour groups.
Seriously. Portal 2. If you have no idea what that means, buy and then play Portal 2.
This little "pool" is actually artificial. That might sound stupid, but it turns out having people coming into the cavern several hours a day, almost every day of the year, means a fair amount of moisture gets trapped in the fabric of people's clothes, and taken out of the cave, drastically lowering the humidity inside the cave, and interfering with natural mineral deposit. So this little "fake pool" is actually crucial in making sure the cavern stays "active".
Seriously. 100 foot winding staircase. Seriously cool.
Most of the spiky bits you see are at least a few feet long. This cavern, is big.
We couldn't pass up a chance to pose with Cthulhu. We survived it, too, so I guess he was just sleeping.