The Mahabharat range, running closely parallel to the Chure range, separates the Terai from the Hill region of Nepal, which covers about 64% of the total land area. This range averages 1,525 to 4,877m altitude and 16kms in breadth. Its structure is synclinal and topography steep and jagged. Forests are usually found on the higher elevations whereas the lower and gentler slopes are used for terraced cultivation.

North of this range and south of the Himalayas, lies the extensively cultivated broad hill complex of the "Pahar" of mountain region, the major subdued in character, this complex has a generally salubrious climate. The fertile valleys formed by the principal river systems, including the Kahtmandu Valley, are the main settlement and cultivation areas in the region.