Kathmandu is the capital and largest urban agglomerate of Nepal. The agglomerate consists of Kathmandu Metropolitan City at its core, and its sister cities Patan, Kirtipur, Thimi, and Bhaktapur. It also includes the recently recognized urban areas of Shankhapur, Karyabinayak, and Champapur. Banepa, Dhulikhel, and Panauti are satellite urban areas of Kathmandu located just outside the Kathmandu valley. Kathmandu is also known informally as "KTM" or the "tri-city". According to a census conducted in 2011, Kathmandu metropolis alone has 975,453 inhabitants; and the agglomerate has a population of more than 2.5 million inhabitants. The metropolitan city area is 50.67 square kilometres (19.56 sq mi) and has a population density of 19,250 per km².
The city stands at an elevation of approximately 1,400 metres (4,600 ft) in the bowl-shaped Kathmandu Valley of central Nepal. It is surrounded by four major mountains: Shivapuri, Phulchoki, Nagarjun, and Chandragiri. Kathmandu Valley is part of three districts (Kathmandu, Lalitpur, and Bhaktapur), has the highest population density in the country, and is home to about a twelfth of Nepal's population.
During Rana and Shah eras, the name "Nepal" referred only to the Kathmandu Valley; it was what people who lived outside the valley called it. During this period, British historians called the valley itself "Nepal Proper". Today, Kathmandu is not only the capital of the Federal Democratic Republic of Nepal, but also the headquarters of the Central Development Region of Nepal. The Central Region comprises three zones: Bagmati, Narayani, and Janakpur. Kathmandu is located in the Bagmati Zone.
Kathmandu is the gateway to tourism in Nepal. It is also the nerve center of the country's economy. It has the most advanced infrastructure of any urban area in Nepal, and its economy is focused on tourism, which accounted for 3.8% of Nepal's GDP in 1995--96. (Tourism in Kathmandu declined thereafter during a period of political unrest, but s