This sparsely vegetated basaltic lava flow was erupted from a fissure vent on the lower SE flank of San Miguel in 1819. The flow covers a broad 2.5-km-wide, 5-km-long area on the low-angle slopes below the volcano and reaches down to an elevation of less than 40 m above sea level. The principal coastal highway of El Salvador traverses the flow below the point of this photo, and the national railway crosses the flow closer to the vent.

Photo by Lee Siebert, 1999 (Smithsonian Institution).

This image is made available under the Public Domain Dedication CC0 license, but proper attribution is appreciated.

San Miguel