Nevado de Incahuasi is a complex volcanic massif that straddles the Chile-Argentina border ENE of Nevados Ojos del Salado volcano.  Two stratovolcanoes occupy a compound 3.5 -km-wide caldera, and Pleistocene lava domes are located on the west and SW flanks of the 6621-m-high volcano.  The youngest stratovolcano is capped by a 1-km-wide crater, and dacitic lava flows radiate down the volcano's flanks.  The fresh-looking morphology of the youngest products of Nevado de Incahuasi suggest a Holocene (González-Ferrán, 1995) or possible Holocene (de Silva 2007, pers. comm.) age.   A dacitic lava dome partially fills an arcuate crater on the eastern flank of Incahuasi  (which means "House of the Inca" in Quechua).  Four pyroclastic cones are located 7 km to NE and produced basaltic-andesite lava flows that cover an area of 10 sq km.