Calderas: Natures Depressions.

Hi Pete, Mike and Jessica Everybody! In case you didn't know, (consider this a Geological courtesy card) calderas exist. A caldera, as defined by praisescience.blogspot.com is a geographical depression due to either a volcano, or other situational, or perceptual factors. Yellowstone National Park is probably the most real caldera of all time, being that it's at the center of three overlapping geographical calderas, and, in retrospect, at the epicenter of one of the most depressing vacations I've been on in a long time. If you're reading this and thinking, "Oh, you mean a crater," you really need a courtesy card. Calderas arise (or depress, rather) from collapsed land after a volcanic eruption, or collapsed spirits from depressing trips. Craters are made by explosions. On the positive, calderas are generally dormant with a few dramatic outbursts, such as old faithful, or me a couple of weekends ago.

Probably the most geologically famous caldera is Santorini, Greece. Check out a live view of the Santorini Caldera