The caldera is bounded by cliffs reaching a height of , which are buried by lava flows from Sairecabur on the northern rim; one of these lava flows reaches the caldera bottom. The pre-collapse volcano was about high and would have been one of the highest volcanoes in the world; Ojos del Salado reaches an altitude of . Sairecabur proper has three cones. Thick () and short lava flows emanated from the northern cone. Glacial erosion has affected Sairecabur and moraines cover some lava flows south of Sairecabur. The total volume of the Sairecabur proper is about .