Sikkim is a Indian state nestled in the Himalayan mountains. The state borders Nepal to the west, China's Tibet Autonomous Region to the north and east, and Bhutan to the southeast, while the state of West Bengal lies to the south.

With around 600,000 inhabitants, Sikkim is the least populous state in India and the second-smallest state after Goa in total area, covering approximately 7,096 km2 (2,740 sq mi). Sikkim is nonetheless geographically diverse due to its location in the Himalayas. The climate ranges from subtropical to high alpine. Kangchenjunga, the world's third-highest peak, is located on Sikkim's border with Nepal. Sikkim is a popular tourist destination, owing to its culture, scenery and biodiversity. It also has the only open border between India and China. Sikkim's capital and largest city is Gangtok.

According to legend, the Buddhist saint Guru Rinpoche visited Sikkim in the 9th century, introduced Buddhism and foretold the era of the monarchy. Indeed, the Namgyal dynasty was established in 1642. Over the next 150 years, the kingdom witnessed frequent raids and territorial losses to Nepalese invaders. It allied itself with the British rulers of India, but was soon annexed by them. Later, Sikkim became a British protectorate, before merging with India following a referendum in 1975.

Sikkim is the only state in India with an ethnic Nepalese majority. Sikkim has 11 official languages: Nepali (which is its lingua franca), Bhutia, Lepcha (since 1977), Limbu (since 1981), Newari, Rai, Gurung, Mangar, Sherpa, Tamang (since 1995) and Sunwar (since 1996). English is taught in schools and used in government documents. The predominant religions are Hinduism and Vajrayana Buddhism. Sikkim's economy is largely dependent on agriculture and tourism, and the state has the fourth-smallest GDP among Indian states, although it is also among the fastest-growing.

History
The earliest historical mention of Sikkim is a record of the passage of the Buddhist saint Guru Rinpoche through the land in the 9th century. The Guru is reported to have blessed the land, introduced Buddhism, and foretold the era of monarchy that would arrive in Sikkim centuries later. In the 14th century, according to legend, Khye Bumsa, a prince from the Minyak House in Kham in eastern Tibet, received a divine revelation instructing him to travel south to seek his fortunes. A fifth- generation descendant of Khye Bumsa, Phuntsog Namgyal, became the founder of Sikkim's monarchy in 1642, when he was consecrated as the first Chogyal, or priest-king, of Sikkim by the three venerated lamas at Yuksom.

Phuntsog Namgyal was succeeded in 1670 by his son, Tensung Namgyal, who moved the capital from Yuksom to Rabdentse. In 1700, Sikkim was invaded by the Bhutanese with the help of the half-sister of the Chogyal, who had been denied the throne. The Bhutanese were driven away by the Tibetans, who restored the throne to the Chogyal ten years later. Between 1717 and 1733, the kingdom faced many raids by the Nepalese in the west and Bhutanese in the east, culminating with the destruction of the capital Rabdentse by the Nepalese. In 1791, China sent troops to support Sikkim and defend Tibet against the Gurkhas. Following Nepal's subsequent defeat, the Chinese Qing Dynasty established control over Sikkim.

Geography
Nestling as it does in the Himalayan mountains, the state of Sikkim is characterized by mountainous terrain. Almost the entire state is hilly, with an elevation ranging from 280 metres (920 ft) to 8,585 metres (28,000 ft). The summit of Kangchenjunga - the world's third-highest peak - is the state's highest point, situated on the border between Sikkim and Nepal. For the most part, the land is unfit for agriculture because of the rocky, precipitous slopes. However, some hill slopes have been converted into terrace farms. Numerous snow-fed streams have carved out river valleys in the west and south of the state. These streams combine into the major Teesta River and its tributary, the Rangeet, which flow through the state from north to south. About a third of the state is heavily forested.

The Himalayan mountains surround the northern, eastern and western borders of Sikkim. The Lower Himalayas, lying in the southern reaches of the state, are the most densely populated. The state has 28 mountain peaks, more than 80 glaciers, 227 high-altitude lakes (including the Tsongmo, Gurudongmar and Khecheopalri Lakes), five major hot springs, and more than 100 rivers and streams. Eight mountain passes connect the state to Tibet, Bhutan and Nepal.

Climate
Sikkim's climate ranges from sub-tropical in the south to tundra in the northern parts. The tundra-type region in the north is clad by snow for four months every year, and the temperature drops below 0 °C (32 °F) almost every night. The peaks of north-western Sikkim are perpetually frozen. Most of the inhabited regions of Sikkim, however, experience a temperate climate, with the temperatures seldom exceeding 28 °C (82 °F) in summer or dropping below 0 °C (32 °F) in winter; the mean monthly summer temperature is 15 °C. The state has five seasons: winter, summer, spring, autumn, and a monsoon season between June and September. The average annual temperature for most of Sikkim is around 18 °C (64 °F).

Sikkim is one of the few states in India to receive regular snowfall. The snow line ranges from 20,000 feet in the north of the state to 16,000 feet in the south. During the monsoon, heavy rains increase the risk of landslides. The record for the longest period of continuous rain in Sikkim is 11 days. In the northern region, because of the high altitude.