El Tatio Geysers
I visited the El Tatio geyser fields back in 2005 while I waiting to cross over to Bolivia from Chile. I remember having a good time at the geyser field waiting for sunrise, and then having eggs boiled in the geysers. The hot springs were pretty nice too. Unfortunately it looks like the geysers will soon be tapped to generate geothermal energy for the nearby copper mines. Visit while you can.
http://www.economist.com/daily/columns/greenview/displaystory.cfm?story_id=13522111
