San Diego volcano is a young basaltic volcanic field near Lake Güija at the border between El Salvador and Guatemala. It contains cinder cones and unvegetated, fresh-looking lava flows.
The lava flows from San Diego volcanic field have created a natural dam to form Lake Güija. The last eruptions of the volcanic field took probably only a few thousands years ago.
Volcanic vents formed mostly in 2 areas: volcanic cones including San Diego east of Lake Güija and an area of small cones north of the lake near the Guatemalan border, north of the Río Ostua.
