The Sepik is travelled rather than visited. The thing to do is to spend a week or more on the river, moving between villages by dugout canoe or motorised longboat, sleeping in the corner of a spirit house or under mosquito netting in a village family's stilt-house, eating sago pancakes and river fish. Most trips start at Pagwi — the only place where a road meets the river — and work downstream into the Middle Sepik, where the spirit-house culture is at its most intense, then on into the lakes country around Chambri.
You go to see the haus tambaran, the great gabled men's houses where ancestor figures and sacred flutes are kept; to watch a master carver at work in a riverside village; to walk into a clan house in the half-dark and find yourself staring at a fifteen-metre face painted with white clay; and to buy carvings or pots that you could not get anywhere else at any price. The travel is hard, slow, and unforgettable. Hire a guide in Wewak or Pagwi and let go of any fixed schedule.