Antisana is a massive, glacier-covered stratovolcano NE of Cotopaxi. The 1.4 x 1.8 km summit crater, seen here from the north, is breached to the SE. Viscous, youthful block lava flows have issued from radial fissures on the flanks of 5753-m-high Antisana. The only unequivocal historical eruption took place from 1801 to 1802. Eighteenth-century eruptions occurred NW of Antisana within Chacana caldera, which lies beneath the cloud bank in the foreground. Photo by Minard Hall, 1975 (Escuela Politécnica Nacional, Quito).