Ambunti is the largest settlement on the upper river and the administrative centre for a district the size of a small European country. There is an airstrip, a market, a post office, and a couple of guesthouses — modest but a luxury after a week on the river. Boats from here head both upstream into the remote Upper Sepik and downstream to Pagwi and the Middle Sepik villages.
The annual Crocodile Festival in early August is the only large tourist event on the river: villages from across the Sepik basin gather to perform clan dances, paint themselves in clay, and demonstrate the ritual scarification that marks initiation into the men's houses. Outside of festival week Ambunti is sleepy, but if you are organising a trip from the western end of the river this is where it begins.