Kathmandu, Aug. 22 -- Ever since Indian troops occupied Kalapani in 1962, the matter has troubled Nepal. Here is an explainer on the six-decade-long history of the dispute.

Where are Kalapani, Lipulekh, and Limpiyadhura?

The 1816 Sugauli Treaty fixed the Kali River as Nepal's western border. Since the river originates in Limpiyadhura, all land east of it-including Kalapani and Lipulekh-belongs to Nepal. Yet a 370 sq km area in Byas Rural Municipality is under India's Pithoragarh District.

Kalapani lies at an elevation of 3,600m, Lipulekh at 5,115m, and Limpiyadhura at 5,500m. Lipulekh was historically a trade and pilgrimage route to Mansarovar, but Nepalis can now only go 22 km short of the pass. India controls the entry gate at Kalapa...