Nepal contains part of the Himalayas, the highest mountains range in the world. Eight of the fourteen eight-thousanders are located in the country, either in whole or shared across a border with China or India. Nepal has the highest mountain in the world, Mount Everest.
Other ranges
North of the Greater Himalayas in western Nepal, ~6,000 metre Tibetan Border Ranges form the Ganges-Brahmaputra divide, which the international border generally follows. South of the Greater Himalayas, Nepal has a High Mountain region of ~4,000 metre summits, then the Middle Hills and Mahabharat Range with 1,500 to 3,000 metre summits. South of the Mahabharats, an outer range of foothills with ~1,000 metre summits is called the Siwaliks or Churiya Hills.
References
List of mountains in Nepal Wikipedia(Text) CC BY-SA