Kathmandu is located in the northwestern part of the Kathmandu Valley, a massive basin situated in the central region of Nepal. The city lies to the north of the Bagmati River, which is the valley's most vital waterway, holding immense religious significance in Hinduism. The Bagmati is joined by several tributaries within the city, including the Bishnumati, Dhobi Khola, and Tukucha, though urbanization has severely impacted the ecological health of these rivers.
The city is completely enclosed by the Mahabharat Range, creating a distinct microclimate and physical barrier. The primary mountains forming this natural fortress are Shivapuri to the north, Phulchowki to the southeast, Nagarjun to the northwest, and Chandragiri to the southwest. This geographic isolation historically protected Kathmandu from invasions but today contributes to modern challenges, particularly air pollution, as the surrounding hills trap smog within the valley.
Natural resources in the immediate geographic area are largely limited to clay, sand, and limestone, which historically supplied the valley's brick and pottery industries. The fertile alluvial soil left behind by the prehistoric lake once made the valley an agricultural powerhouse, though rapid urbanization has since covered most of the arable land with concrete infrastructure.