Geography of Trinidad and Tobago passage. Trinidad is traversed by three distinct mountain ranges that are a continuation of the Venezuelan coastal cordillera. The Northern Range, an outlier of the Andes Mountains of Venezuela, consists of rugged hills that parallel the coast. This range rises into two peaks. The highest, El Cerro del Aripo, is high; the other, El Tucuche, reaches . The Central Range extends diagonally across the island and is a low-lying range with swampy areas rising to rolling hills; its maximum elevation is . The Caroni Plain, composed of alluvial sediment, extends southward, separating the Northern Range and Central Range. The Southern
Nevado San Francisco They are noteworthy for their olivine phenocrysts. One lava flow less than one million years old reaches a length of . The western slopes contain dacitic lava domes. On the summit lie two circle-shaped constructs, of Inca or Formative period ages. Nevado San Francisco Nevado San Francisco, or Cerro San Francisco (), is a stratovolcano on the border between Argentina and Chile, located just southeast of San Francisco Pass. It is considered extinct and is one of the several peaks in the area, of which the chief is the Ojos del Salado. The volcano is part of the Central Volcanic