乃堆拉山口
Nathu La has moderately shallow, excessively drained, coarse, and loamy soil on a steep slope (30–50%) with gravelly loamy surface, moderate erosion, and moderate stoniness. It has several sinking zones and parts of it are prone to landslides. To preserve the fragile environment of Nathu La on the Indian side, the government of India regulates the flow of tourists. Road maintenance is entrusted to Border Roads Organisation, a wing of the Indian Army. On the Chinese side the pass leads to the Chumbi Valley of the Tibetan Plateau.