Cerro Blanco lies at an elevation of and consists of four nested calderas with discontinuous borders, fallout deposits, lava domes and pyroclastic deposits. The two inconspicuous El Niño and Pie de San Buenaventura calderas are nested in the northern part of the complex and form a wide depression. Only their northern margins are recognizable in satellite images; their southern parts are filled with block and ash flows from the southern calderas. The southern calderas are the Robledo and Cerro Blanco calderas, which form a southeast-northwest trending pair. Alternative interpretations consider the Pie de San Buenaventura, Robledo and Cerro Blanco calderas as one caldera, that the Robledo and Cerro Blanco calderas are one system or envisage the existence of only three calderas.