Nepal's physical geography is characterized by extreme verticality, packing immense ecological variety into a relatively small area. The country is broadly divided into three distinct ecological belts running east to west: the Terai (lowland plains), the Pahad (middle hills and valleys), and the Himal (high mountains). The Terai is a fertile, subtropical extension of the Indo-Gangetic plain, boasting rich alluvial soils and dense jungles that host incredible wildlife, including the Bengal tiger and one-horned rhinoceros.
Moving north, the elevation rises sharply into the Pahad region. This area encompasses the Mahabharat Range and the lower Churia Hills, characterized by steep, terraced slopes, fast-flowing rivers, and temperate forests. The Pahad is the traditional heartland of Nepal, heavily populated and containing the expansive Kathmandu and Pokhara valleys.
In the extreme north lies the Himal region, a spectacular high-altitude wilderness containing eight of the world's ten highest mountains. This area features massive glaciers, deep river gorges, and alpine tundras. The geography is carved by massive, snow-fed river systems—primarily the Koshi, Gandaki, and Karnali—which slice through the mountain ranges as they flow south into India. This rapid change in elevation creates exceptional biodiversity and immense hydroelectric potential.