Bhutan is a land lock south Asian country, an area of 38,394 sq.km. It stretches 300km from east to west, 140 from north to south.

There are many versions of how the country got its name, first suggested that it is derived from ‘Bhotana’ (end of Tibet) or from ‘Bhu-utan’ (high land). Another theory suggest that the name evolved from the word ‘Bhot-stan’, the land of the Bhotias (in the ancient Indian language Sanskrit, people originally from Tibet were called ‘bhotia’). Bhutanese proudly call their country as Drukyul (Land of Thunder Dragon) and themselves as ‘Drukpas’.

Bhutan is in the central Himalayan region bounded by the high Himalayas running north to east on the northern border (7000m high). However, the land is further sub-divided by a series of mountain ranges that are (4000m to 5000m high), and run north to south which creates a series of valleys with the veritable independent eco-system.
The major geographical zone is the northern region, lying above 11480ft/3500m height of greater Himalayas. To the east lie the four valleys (ranging from 8,856ft to 13,120tf/2700m to 4000m). Jomolhari (24,000ft/7314m) is the Bhutan’s highest peak. A large part of this ranges are covered by snow throughout the year. There are many fast flowing streams and river which is known as ‘Chu’ and the central Himalayas bear the brunt of the monsoon, the river are large and powerful.

Most of rivers have their source from high mountains but the Himalaya range is not a continental divide, and there are three rivers that actually flow through the mountains. The Amo Chhu flows from Tibet’s Chumbi valley across the southwestern corner of Bhutan, where it becomes the Torsa Chhu, and exits at Phuentsholing. Two tributaries of the Manas, in eastern Bhutan, originate outside the country. The Kuri Chhu has its source in Tibet (where it is known as the Lhobrak Chhu) and crosses into Bhutan elevation of 1200m; the other tributary, the Gamri Chhu, rises in India’s Aurnachal Pradesh. The Thimphu Chhu, known as the Wang Chhu, eventually becomes the Raidak River in India. The Pho Chhu and Mo Chhu join at Punakha to form the Puna Tsang Chhu, which flows between the Dochu La and the Black Mountains. This river is known as Sankosh when it reaches to India. The manas is Bhutan’s largest river, it flows about two-thirds of the country, Mangde Chhu flows from Trongsa and joins the Manas Chhu just before it flows into India.