The Sikkim Himalayas, the epitome of the world's mountains, encompass a wonderland, which for sheer beauty and magnificence remains unbeaten elsewhere in the globe. In the southwestern part of Sikkim, in the main Himalayan range, lies the majestic Khangchendzonga or Kanchenjunga, rising to a staggering height of 8,585 m (28,169 ft) above sea level. Beside this third largest peaks, other famous mountaineering peaks in (7,365 m) and Sinolchu (6,887 m). Mountaineering expeditions, unlike trekking, require more planning and paperwork as clearance is required from the Indian Mountaineering Foundation, New Delhi. Besides these the local governments also impose royalties on certain peaks. The first European to explore the Kanchenjungha area was Douglas W. Fresfield who

reached its base in 1899 from the Green Lake Basin area. A German expedition led by Paul Bauer made the first attempt to reach the summit in 1929 followed by another attempt in 1931 and reached an altitude of 26,000 ft. In 1955 Charles Evans conquered Kanchenjungha a few feet below the summit from the Nepal side.

In 1977 an expedition led by Major Prem Chand reached a few feets below the summit. In 1987, an Assam Rifles expedition attempted the peak. In 1991 an Indo Japanese expedition led by Hukam Singh and Yoshio Ogata conquered the peak. The Kabru was first climbed in 1935 by a British C. R. Cooke. The Pyramid Peak was first conquered in 1949 by a Swiss R. Dittert. A British A. M. Kallas, climbed the Paunhri in 1911.

The summit of Siniolchu was first reached by a German in 1936. It was later again climbed by the famous Sikkimese Everester Sonam Gyatso. Pandim was climbed in 1993 by a team from the Sonam Gyatso Mountaineering Institute. Rathong was conquered by an Indian expedition in 1964.