This weekend we took a couple hours and went to see Laguna de Olomega, which is on the border between the departments of San Miguel and La Union. For $15, we got a tour around five of the islands and stopped at one of them to see some petroglyphs. To me, Olomega is much more worth seeing than Coatepeque and some of the other volcanic lakes, mostly because of the floating water plants and the birds. It also has pockets of boiling water, which is nifty as long as you don't have to get close to it. There was tasty lake tilapia for lunch, swimming pigs, friendly locals, and really adorable little kids, which makes all the difference!