For a country of its size, Nepal has tremendous geographic diversity. It rises from as low as elevation in the tropical Terai—the northern rim of the Gangetic Plain, through beyond the perpetual snow line to 90 peaks over including Earth's highest ( Mount Everest or Sagarmatha). In addition to the continuum from tropical warmth to cold comparable to polar regions, average annual precipitation varies from as little as in its narrow proportion of the rainshadow north of the Himalayas to as much as on windward slopes, the maximum mainly resting on the magnitude of the South Asian monsoon.