Tajumulco is Guatemala's highest peak and the highest volcano in Central America. Two summits, one with a 50-70 m wide crater, lie along a NW-SE line. A lava flow from the ~4200-m-high NW summit traveled down a deep valley on the NW flank. The andesitic-dacitic volcano was constructed over the NW end of a large arcuate SW-facing escarpment of uncertain origin. Tajumulco has had several unconfirmed reports of historical eruptions. Sapper (1917) considered it to have erupted during historical time, but without accurate dates. The volcano was reported to eject many rocks, destroying houses on 24 October 1765, but this may have been a rock avalanche. Juarros reported some eruptions before 1808, and there are unlikely reports of eruptions in 1821 (or 1822), 1863, and 1893 (Incer 1988, unpublished manuscript).