As the Zagros continue into southeastern Iran, the average elevation of the peaks declines dramatically to under . Rimming the Caspian Sea littoral is another chain of mountains, the narrow but high Alborz Mountains. Volcanic Mount Damavand, , located in the center of the Alborz, is not only the country's highest peak but also the highest mountain on the Eurasian landmass west of the Hindu Kush.