Ladakh (Tibetan: ལ་དྭགས, Wylie: La-dwags, Ladakhi [lad̪ɑks], Hindi: लद्दाख़, Urdu: لدّاخ [ləd̪ˈd̪aːx]; "land of high passes") is a region of India in the state of Jammu and Kashmir and lies between the Kunlun mountain range in the north and the main Great Himalayas to the south, inhabited by people of Indo-Aryan and Tibetan descent. It is one of the most sparsely populated regions in Jammu and Kashmir.
Historically, the region included the Baltistan (Baltiyul) valleys, the Indus Valley, the remote Zangskar, Lahaul and Spiti to the south, Aksai Chin and Ngari, including the Rudok region and Guge, in the east, and the Nubra valleys to the north.
Ladakh is the highest altitude plateau region in India (much of it being over 3,000 m), straddling the Himalayan and Karakoram mountain ranges and the upper Indus River valley.
The mountain ranges in this region were formed over a period of 45 million years by the folding of the Indian Plate into the stationary landmass of Asia. While the Himalayas were formed from the base material of the Indian plate, the Zanskar Range consists of layers of sediment from the ocean floor, and the Ladakh Range of granite was born of the immense heat generated by the friction between the two plates. In Ladakh, the suture zone between the continental masses runs a little to the south of the Indus Valley. The drift continues and is the cause of the frequent earthquakes in the Himalayan region. Crossing the Himalayas by the dip of the Zoji-la, the crest-line of the range remains at a relatively modest level, the highest peaks near the pass being little more than 5000–5500 m above sea level. South-east of Zoji-la the scale increases, reaching a climax in the mighty massif of Nun-Kun, with two summits over 7000 m.
The Suru and Zanskar valleys form a great trough at the foot of the northern, heavily glaciated flank of the Himalayas, while opposite rise the mountains of the Zanskar range. The Suru River forms the western and northern boundary of the Zanskar range. The Suru, after receiving the combined waters of the Dras and Shingo Rivers a short distance north of Kargil, joins the Indus at Marol in Baltistan, which is now on the Pakistan side of the Line of Control. Rangdum Monastery and the attendant village of Julidok is the last inhabited region in the Suru valley; it is also the destination of the nomadic herdspeople called Bakarwals, who trek up every summer from the Jammu region. From Rangdum the valley rises to 4400 metres at the Pensi-la, the gateway into Zanskar. Kargil, the only town in the Suru valley, was an important staging post on the routes of the trade caravans before 1947, being more or less equidistant, at about 230 kilometres from Srinagar, Leh, Skardo, and Padum. Rangdum, though on the northern side of the Pensi-la, is regarded as socially and culturally part of Zangskar rather than of Suru.