San Francisco Pass it passes next to Maricunga's salt flat on the Nevado Tres Cruces National Park and Laguna Verde. The area is surrounded by volcanoes and high peaks as the Cerro Falso Azufre (), the volcano San Francisco (), the Incahuasi () and highest volcano in the world, Nevado Ojos del Salado (), among others. San Francisco Pass The San Francisco Pass is a pass over the Andes mountains which connects Argentina and Chile. The highest point of this pass is at AMSL. The pass is located at and connects the Argentine province of Catamarca with the Atacama Region in Chile. In
Ojos del Salado of fumaroles high on the mountain and recent-looking lava flows, albeit of uncertain age, also argues in favor of a categorization as "active." By these definitions, Ojos del Salado is the highest historically active volcano on Earth. If the older date is accepted, the title of "highest historically active volcano" might reside instead with the somewhat lower Llullaillaco volcano, which certainly has erupted in historic times (most recently in 1877) and is considered active. Salado's rock is predominantly potassium-rich dacite and rhyodacite. Its lavas are high in biotite, hornblende, plagioclase, and opaques, with lower levels of augite, quartz, and hypersthene.