It is a place that overwhelms at first, with narrow lanes, shrines on every corner, motorbikes and tuk-tuks, and the smell of incense, diesel and frying dough. On a clear morning, snow peaks appear to the north, a surprise after the haze.
The Prithvi Highway starts here and runs west to Pokhara, about two hundred kilometres, through some of the loveliest and most chaotic riding in Asia. It climbs out of the valley over the rim, drops into the gorge of the Trishuli river and follows it, with tight bends, steep slopes and trucks and buses that overtake on blind corners. The surface can be rough, with potholes, landslides in the monsoon and long delays at bad sections. A day's ride can take seven or eight hours or more, so start early, ride defensively and be ready for sudden stops. Nepali traffic drives on the left.
The valley has an extraordinary heritage. Durbar Square, with its carved wooden temples, was badly damaged in the 2015 earthquake, and restoration continues. Swayambhunath, a hilltop stupa with watching eyes, is known as the Monkey Temple, and Boudhanath, one of the largest stupas in the world, is the centre of Tibetan Buddhism in Nepal. Pashupatinath, a Hindu temple complex on the Bagmati river, is a place of cremations and pilgrimage. The city's Newar people have a rich cuisine, with momo dumplings and spiced meat dishes.
Fuel is available in Kathmandu, but shortages occur from time to time, so fill up whenever you can. There are stations along the highway, though the supply is not always reliable. Cafes and small restaurants serve dal bhat, the rice and lentil meal that is the national dish.
Carry a mask for the dust and keep your visor clean. A good start in the early morning, before the traffic, makes the day easier.