Nepal is a landlocked country situated in the central part of the Himalayas between India and China. It has tremendous geographic diversity that ranges from tropical alluvial plains in the south to the very rugged and permanently snow and ice covered Himalayan Mountains in the north. The country can be divided into five major physiographic zones, namely, from north to south, the High Himal, High Mountains, Middle Mountains, Siwalik Hills and Tarai Plains. All five zones extend lengthwise from east to west across the country. The climate varies from alpine cold semi-desert type in the trans-Himalayan zone to tropical humid type in the tropical lowlands in the south.