Sikkim has a very rugged topography and the flat lands are difficult to come by. The towering mountains that define this paradise of the nature also create a barrier to efficient agriculture.
These ranges form an almost impregnable barrier. On the western boarder lies the third highest mountain of the world Kanchendezonga, 28,168 ft. High. Other peaks that deserve mention are Siniolchu, Pandim, Narsing, Kabru, Pyramid Peak and Nepal Peak.
Through the center of sikkim runs another mountain ridge in the North to South direction. This mountain ridge separates the
Glaciers are moving mountains of ice. There are many of these in Sikkim, but the most important ones are: Zemu Glacier, Rathong Glacier, Lonak Glacier in North Sikkim.
The mountain ranges are interspersed with the passes which can be used to cross from one side to another. On the Eastern Chola range the most important passes are the Nathu La and Jelep La both at an altitude of about 15,0000 ft. and Bhutah La at an altitude of about 13,000 ft. The first two lead to Tibet and the third to Bhutan.
On the west boarder of Sikkim and Nepal, the most important pass is Chiwabhangjang, which has an altitude of 10,300 ft. The other passes on the west is Kang La. In the north one of the important passes is the Kongra La.