The Himalayas (above 3,000 m) comprises mountains, alpine pastures and temperate forests limited by the tree-line (4,000 m) and snow line (5,500 m). 8 of the 14 eight-thousand meter peaks of the world lie in Nepal: Sagarmatha or Mount Everest (8,848 m), Kanchenjunga (8,586 m), Lhotse (8,516 m), Makalu (8,463 m), Cho Oyu (8,201m), Dhaulagiri (8,167 m), Manaslu (8,163 m) and Annapurna (8,091 m). The inner Himalayan valley (above 3,600 m) such as Mustang and Dolpa are cold deserts sharing topographical characteristics with the Tibetan plateau. Nepal holds the so called waters towers of South Asia with its 6,000 rivers which are snow-fed or dependent on rain. The perennial rivers include Mahakali, Karnali, Narayani and Koshi rivers originating in the Himalayas. Medium-sized rivers like Babai, West Rapti, Bagmati, Kamala, Kankai and Mechi originate in the Midlands and Mahabharat range. A large number of seasonal streams, mostly originating in Siwaliks, flow across the Terai.
The nine globally recognized Samsar sites are: Koshi Tappu Wildlife Reserve, Beeshazarital (Chitwan), Jagdishpur Reservoir (Kapilvastu) Ghodaghodi Tal (Kailali) in the Terai, and Gokyo (Solukhumbu), Phoksundo (Dolpa), Rara (Mugu) and Mai Pokhari (Ilam) in the mountain region. There are more than 30 natural caves in the country out of which only a few are accessible by road. Maratika Cave (also known as Haleshi) is a pilgrimage site associated with Buddhism and Hinduism. Siddha Cave is near Bimalnagar along the Kathmandu-Pokhara highway. Pokhara is also known for caves namely Bats shed, Batulechar, Gupteswar, Patale Chhango. The numerous caves around Lo Manthang in Mustang include Luri and Tashi Kabum which house ancient murals and chhortens dating back to the 13th century.