Kathmandu is the capital and largest city of Nepal, with a population of around 845,000 in the city proper and roughly four million across the surrounding valley. It sits at about 1,324 metres in the Kathmandu Valley, a bowl in the middle hills between the Himalaya and the Indian plains — and almost everything distinctive about the city follows from that bowl.
The valley came first
Kathmandu is unusual among capitals in that the surrounding region has a name and an identity older and more meaningful than the city's own. The Kathmandu Valley — historically Nepal Mandala — is an oval basin roughly 25 km across, ringed by hills rising to around 2,700 metres, with the Bagmati river draining it through a single gorge in the south.
Geologically it was a lake. Sediments beneath the valley floor run hundreds of metres deep, laid down when the basin held standing water before the Bagmati cut its outlet. Local tradition tells the same story differently: the bodhisattva Manjushri struck the valley wall with his sword at Chobar to drain the lake and make the land habitable. The gorge at Chobar is real, and it is exactly where the water leaves.
That flat, deep, fertile lake-bed soil in the middle of a mountain country is why a substantial urban civilisation grew here rather than anywhere else in Nepal. The valley could feed a dense population when the surrounding hills could not.
Three cities, three durbar squares
For much of its history the valley did not have one capital but three competing ones. Kathmandu, Patan (Lalitpur) and Bhaktapur were separate Malla kingdoms, each with its own royal palace complex, and their rivalry ran for centuries.
The rivalry is the reason the valley is so architecturally rich. Three courts competing on prestige built three sets of palaces, temples and public squares within a few kilometres of one another, each trying to outdo the others. The Newar craftsmen who built them — the valley's indigenous people, whose language and civic culture shaped the whole region — produced a tradition of brick and carved timber architecture found nowhere else.
The result is that the Kathmandu Valley holds seven UNESCO World Heritage monument zones inside a single site inscription: the three Durbar Squares, the Buddhist stupas of Swayambhunath and Boudhanath, and the Hindu temple complexes of Pashupatinath and Changu Narayan. Very few places anywhere concentrate that much protected heritage in that little space.
Unification ended the rivalry. Prithvi Narayan Shah of Gorkha took the valley in 1768–69 and made Kathmandu the capital of a single Nepali state, which it has been ever since.
What the 2015 earthquake did
On 25 April 2015 a magnitude 7.8 earthquake struck central Nepal, killing around 9,000 people nationally and destroying or damaging a very large number of buildings in the valley.
The heritage losses were severe and specific. The Dharahara tower collapsed entirely. Substantial parts of Kathmandu and Bhaktapur Durbar Squares came down, and temples that had stood for centuries were reduced to their plinths. Reconstruction has been slow, contested and in places genuinely impressive, using traditional timber joinery and salvaged carved elements rather than concrete substitutes.
The underlying cause is not going away. Nepal sits on the collision zone where the Indian plate drives beneath Asia — the same convergence that raises the Himalaya — and the Kathmandu Valley's deep lake sediments amplify seismic shaking, so the basin shakes harder and longer than the rock hills around it. A 1934 earthquake had done comparable damage eighty years earlier. The valley's building stock, much of it added rapidly and informally since the 1990s, remains the central risk.
The air that cannot get out
The same topography that made settlement possible traps what the city emits. Cold air pools on the valley floor overnight and a temperature inversion caps it, so vehicle exhaust, brick-kiln smoke and construction dust accumulate rather than dispersing — and the ring of hills prevents lateral clearance.
Kathmandu consequently records some of the worst urban air quality readings in the world during the winter months, and the pattern is seasonal rather than constant: the monsoon washes the air clean between roughly June and September, and the worst readings come in the dry, still period from December to March.
Brick kilns ringing the valley, a vehicle fleet that grew far faster than the road network, and open burning all contribute. The problem is a direct product of putting several million people in an enclosed basin, and it is not solvable by any measure that does not address what enters the air in the first place.
What the name means
Kathmandu takes its name from Kasthamandap, a large public pavilion on the edge of the Durbar Square whose name means wood shelter — traditionally said to have been built from the timber of a single tree. It was not a temple but a rest house on the trade route, which is a fair summary of what the city was for.
Kasthamandap collapsed in the 2015 earthquake. Excavation of the site afterwards found evidence pushing its origins back considerably earlier than previously assumed, and it has since been rebuilt using traditional methods. A city named after a building that fell down and was put back up is an unusually apt piece of nomenclature.
Gateway to the mountains, and what that pays for
Tourism is a large part of the city's economy, and most of it is transit rather than destination: Kathmandu is where trekkers and climbers arrive, buy permits, hire guides and fly on to Lukla or Pokhara. Thamel, the tourist quarter, exists almost entirely to serve that traffic.
Tribhuvan International Airport is the country's only international airport of significance, which concentrates an entire nation's air access in one valley with difficult approach terrain and a single runway. Expansion has been constrained by exactly the topography that defines everything else here.
The relationship with the mountains is economic and cultural at once. Expedition outfitting, Sherpa employment, permit revenue and the hotel trade all depend on Everest and its neighbours being 150 km away, and the city's fortunes track the climbing and trekking seasons closely — as the collapse in arrivals after 2015 and again during the pandemic demonstrated.
The road between India and Tibet
Before it was a tourist gateway, Kathmandu was a trading one. The valley sat on the route between the north Indian plains and the Tibetan plateau, and Newar merchants worked that corridor for centuries — carrying grain, cloth and metalwork north, and salt, wool and Tibetan goods south.
Newar traders maintained a permanent presence in Lhasa, and the traffic ran both ways culturally as well as commercially. The Nepalese artist Araniko was sent north in the thirteenth century and became an influential figure at the Yuan court, credited with the white stupa in Beijing; the pagoda roof form itself is often traced along this corridor.
The trade largely ended after 1959 and the closure of the Tibetan frontier, and Kathmandu's economy reoriented toward India, aid and eventually tourism. But the wealth that built the valley's temples and the technical tradition of its metalworkers came from that Himalayan crossing, not from the country around it.
A capital of festivals and living temples
Kathmandu's religious life is unusual for how thoroughly Hindu and Buddhist practice interpenetrate. Many shrines are venerated by both traditions, often under different names, and the Newar religious calendar accommodates both without treating them as alternatives.
Pashupatinath, on the Bagmati, is among the most significant Shiva temples anywhere and functions as a working cremation ground. Boudhanath is one of the largest stupas in the world and the centre of Tibetan Buddhist life in Nepal, its surrounding neighbourhood substantially shaped by refugees who arrived after 1959.
The festival calendar is dense: Indra Jatra, Dashain, Tihar, and Bisket Jatra in Bhaktapur, several involving chariot processions through streets that were laid out for exactly that purpose. The Kumari — a young girl venerated as a living goddess, who appears publicly at certain festivals from her house on Kathmandu Durbar Square — is the practice outsiders find most remarkable, and it is genuinely continuous rather than revived.
A city outgrowing its bowl
Kathmandu's population has multiplied several times over since the 1990s, driven by rural migration, by displacement during the Maoist insurgency of 1996–2006, and by the concentration of jobs, schooling and administration in one place.
The valley has absorbed that growth by building on its own farmland. Fields that fed the valley for a thousand years are now housing, and the resulting sprawl has run ahead of water supply, sewerage and road capacity. Groundwater extraction has lowered the water table; the Bagmati, sacred along its whole length, runs badly polluted through the city.
The Melamchi project, which pipes water from a neighbouring valley through a 26 km tunnel, was conceived to address supply and has been repeatedly delayed and damaged by flooding. It is an apt summary of the city's position: a settlement whose site was ideal for a pre-industrial population of tens of thousands, carrying several million, in a seismically active basin with one river out and no easy way to expand. For the wider country, see our Nepal country guide.