Nepal measures about 800 kilometers (497 mi) along its himalayan axis by 150 to 250 kilometers (93 to 155 mi) across. With 147,181 square kilometers (56,827 sq mi) it slightly outranks Bangladesh or the state of Arkansas. Nepal is landlocked by India on three sides and China's Xizang Autonomous Region (Tibet) to the north. West Bengal's narrow Siliguri Corridor or Chicken's Neck separate Nepal and Bangladesh. To the east are India—and Bhutan. Nepal depends on India for transit facilities and access to the sea—the Bay of Bengal—even for most goods imported from China.

Geographic coordinates: 28°00′N 84°00′E / 28°N 84°E / 28; 84

For a small country, Nepal has tremendous geographic diversity. It rises from less than 100 metres (328 ft) elevation in the tropical Terai—the northern rim of the Gangetic Plain, beyond the perpetual snow line to some 90 peaks over 7,000 metres (22,966 ft) including Earth's highest 8,848 metres (29,029 ft) Mount Everest or Sagarmatha. In addition to the continuum from tropical warmth to cold comparable to polar regions, average annual precipitation varies from as little as 160 millimetres (6.3 in) in the rainshadow north of the Himalaya to as much as 5,500 millimetres (216.5 in) on windward slopes.

Nepal (नेपाल) (ⁱ/nɛˈpɔːl/ ne-PAWLNepali: नेपाल [neˈpal] ( listen)), officially the Federal Democratic Republic of Nepal, is a landlocked sovereign state located in South Asia. It is located in the Himalayas and bordered to the north by the People's Republic of China, and to the south, east, and west by the Republic of India. Specifically, the Indian states of Uttarakhand, Uttar Pradesh, Bihar, West Bengal, and Sikkim border Nepal, while across the Himalayas lies the Tibetan Autonomous Region. With an area of 147,181 square kilometres (56,827 sq mi) and a population of approximately 27 million (and 2 million absentee workers living abroad), Nepal is the world's 93rd largest country by land mass and the 41st most populous country. Kathmandu is the nation's capital and the country's largest metropolis. Kathmandu Valley itself has estimated population of 5 million.

Nepal has a rich geography. The mountainous north has eight of the world's ten tallest mountains, including the highest point on Earth, Mount Everest, called Sagarmatha in Nepali. It contains more than 240 peaks over 20,000 ft (6,096 m) above sea level. The fertile and humid south is heavily urbanized.

Toni Hagen (August 17, 1917 in Luzern – April 18, 2003 in Lenzerheide) was a Swiss geologist and a pioneer of Swiss development assistance. After taking a diploma in engineering and geology from the Swiss Federal Institute of Technology in Zurich, he took a doctorate in the geology of the Welsh mountains and then became a research assistant at the Zurich Geological Institute. Hagen first visited Nepal in 1950 with a first Swiss development assistance mission. In 1952 he was employed by the government of Nepal and also worked for the United Nations. He explored the geography of that Himalayan state.

Dr. Hagen was the first foreigner to trek throughout Nepal during geological and geographic survey work and mapping on behalf of the United Nations. He clocked over 14,000 km walking several times across Nepal, where the topography is mostly hilly to snow-covered. He filmed Nepalese cultural and ethnic diversity originally as produced as a silent documentary, and later with an English narration in his own voice. Dr. Hagen is also the author of several books including a book entitled Nepal (ISBN 99933 13 03 3; LCCN 99937099)