Los Ausoles is located in the department of Ahuachapan, right outside the city of the same name by the geothermic plant La Geo. They're smoke-spewing fumaroles (vents?) that you can walk right up to, as well as boiling mud and hot springs. Smelled a bit like when the water softener at home in Ohio isn't working, but stronger. The best part was that it was just kinda there, free for anyone to walk right up to (or into if you weren't paying attention). Los Ausoles is defenitely on my list of cool things that I've seen in El Salvador that most people don't even know exist. Next stop is the Termales de Santa Teresa right down the road.
The vents make a hissing sound, just like a pressure cooker. Not a particulary comforting thought when you're walking over top of them.