Kathmandu (Nepali: काठमाडौं[kɑʈʰmɑɳɖu]; Nepal Bhasa: येँ देय्) 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.
Durbar Square is the generic name used to describe plazas opposite old royal palaces in Nepal. Before the Unification of Nepal, Nepal consisted of small kingdoms, and Durbar Squares are most prominent remnants of those old kingdoms in Nepal. In particular, three Durbar Squares in the Kathmandu Valley, belonging to the three kingdoms situated there before unification, are most famous: Kathmandu Durbar Square, Patan Durbar Square, and Bhaktapur Durbar Square. All three are UNESCO World Heritage Sites.