El Salvador is a volcanic belt. To that end you will find many active and dormant volcanoes here. Most of these volcanic areas have flora and fauna quite endemic to the region. Take for instance the Coatepeque Caldera. It looks like a huge caldera and was formed due to a series of rhyolitic explosion in between 72,000 and 57,000 years ago. The main features here, as in all volcanic structures are cinder cones of basalt and lava flows which are accumulated in the west end of the caldera. There are also six lava domes out of which the youngest is the Cerro Pacho formed way back in 8000 BC. From this we get an idea about the antiquity of the region.
On the Eastern side of the Coatepeque Caldera is a large crater lake known as the Lake Coatepeque. Many hot springs can be found near this waterbody. The small native Island of Teopan is located here. This Island has religious significance for the Incas. Geologically speaking the lake was formed when some huge strato volcanoes collapsed on the Eastern part of Santa Ana volcanic region. After the lava from the caldera cooled down it resulted in the formation of cinder cones and lava domes. The largest of these domes is now the forested island of the Isla de Cabra.
The area around the Coatepeque Caldera is far from being uninhabited. It is one of the most populated regions in El Salvador due to its rich and fertile soil.Santa Ana, one of the main cities of El Salvador is at a distance of ten kilometers from here. Eevn coffee plantation is quite popular here especially at an elevation of 600-1700 m. It is quite easy to reach the area from Santa Ana. . The market of El Congo marks the lake exit and you have to drive south to reach the caldera. There are two trails to the caldera. Both covers about three fourth portion of the lake as well. The lake is a thriving area with private homes and hotels lining it. If you want to experience the sheer delight of bathing in hot springs take the western side of the Lake which will take you to Cerro Pacho, Afate and Cerro la Isla. These are also some of the domes formed from the volcanic eruptions.
At present everything is quiet in the El Salvador front with no active eruptions from the volcanoes. At the most there were some weak fumes from the sides of Cerro Pacho and Cerro Afate domes. On the way to the lake there are two miradores which gives you a perfect view of the volcano in its full glory. The whole area when viewed in totality gives a picture of a giant green region with a beautiful blue lake in the middle. The two nearby volcanoes of Santa Ana and Izalco are as beautiful. Only the greenery turns into rock and ash in the Santa Ana volcanic region