The Sepik is a region of Papua New Guinea, consisting of two provinces, East Sepik and West Sepik.
- East Sepik has an population of around 400,000. There are a few offshore islands and coastal ranges just inland. Much of the province's geography is dominated by the Sepik River, which flows briefly also through the Papua province of Indonesia and is one of the largest rivers in the world in terms of water flow. Its level can alter by as much as five metres in the course of the year. In the south of the province are mountain ranges that form part of the Sepik's large catchment area that includes swamplands, tropical rainforests and mountains.
European contact on the river began in 1885, when the Germans explored the area. Tourist trips up and down are possible. It is best visited in June to November when there are less mosquitoes. For the truly adventurous it should be possible to rent dugout canoes with outboards and boatman at the river villages closest to the province's capital, Wewak. The people living along the river are noted for their carvings and elaborate manhood initiation ceremonies. Many villages use garamut drums, which are long, hollowed-out tree trunks carved into the shape of totem animals. Many villages have a Haus Tambaran which is a traditional ancestral worship house. The most recognizable forms of this are found around the village of Maprik. The Sepik people are renowned for their superb artistic ability in painting and carving, which is often exhibited in these religious structures. Papua New Guinea's first prime minister, Michael Somare, came from the Sepik region and it is perhaps no coincidence that the design of the country's parliament building in Port Moresby was based on a Haus Tambaran.
- West Sepik is also known as Sandaun (sun down) province, as it is, with Western Province, the most westerly of PNG's provinces. The name Sandaun was adopted by the province in order to differentiate it from East Sepik. It is a large province with mountains in the interior, jungles in the lowlands, and attractive tropical coastlines. There are limited road connections along the coast and most inland districts can only be reached by light aircraft or boats. The interior townships of Telefomin and Oksapmin are said to be the most remote towns in the country.
The capital of West Sepik is Vanimo, which is a stopping off point for those heading for Indonesia and for expats in Indonesia wanting to renew their Indonesian visas. It is also becoming a popular destination for expert surfers. Also on the coast is Aitape, a town developed around a catholic mission. Close to there is the Sissano Lagoon which was devastated by a tsunami in 1998, killing 2000.
- Wewak, capital of East Sepik province and gateway to the Sepik river.
- Vanimo, capital of West Sepik or Sandaun province and border town for Indonesia.
- East Sepik Islands. Three small islands just half an hour off the coast from Wewak. Kairiru is volcanic and Mushu a coral atoll with abundant reef fish. Robuin currently has no inhabitants and is owned by the people of Wom village. It was used as a fuel dump by the Japanese during World War 2 and extensively bombed by the allies during the Aitape-Wewak campaign which culminated in the surrender of all Japanese forces in PNG by General Adachi. There are a couple of basic guesthouses on Mushu and one on Kairuru.
- Wuvulu island. Wuvulu is the most western of the islands off Papua New Guinea's north coast, collectively known as the Bismark Archipelago. It has a 12 mile circumference, with a surface area of 1,400 ha. The island is flat, nowhere rising above 2m. The population of around 1000 depend on sweet potato, taro and cassava as staples, plus coconut, cabbage and lots of fish. They live in two main villages and build wooden houses on stilts to maximise the flow of the breeze. Wuvulu is completely encircled by a coral reef and there is no natural harbor. Jacques Cousteau described it as having some of the world's best diving.
The Sepik has the highest concentration of languages in all of Papua New Guinea (and therefore by extension, in the world). Many people speak Tok Pisin (pidgin) to some extent, few speak English. It facilitates your stay quite a bit if you try to learn some basic pisin words and phrases (locals will be all too pleased to help if asked, and will take great delight in teaching you). When traveling away from Wewak, it is very worthwhile to get a guide to help you in the villages. Conflicts between villages and different language groups is common, and it is a good idea to quiz your guide about current events, his origins and affiliation with the villages you intend to visit.
- Air Niugini has daily flights to Wewak and regular flights to Vanimo from PNG's capital Port Moresby, Nadzab (Lae) and Madang. 
The provinces depend heavily on Mission Air Fellowship (MAF), which operates twelve planes throughout PNG both supplying mission stations and supporting local communities. It is sometimes possible for tourists to fly with MAF.
- A Haus Tambaran. The best examples of these are around the Maprik area of East Sepik. The male-dominated tambaran culture uses the haus tambaran as a meeting-house and site for rituals and initiations, as well as for worship for the yam cult, the yam being the staple food for the Sepik people. A giant spirit is personified as noises that can be heard coming from the haus tambaran. Haus tambarans contain many paintings. Their preparation is a sacred activity for the Sepik people, and the paintings are taken very seriously.
- Travel along the Sepik River. This is Papua New Guinea's Amazon and is navigable for most of its length. It is full of amazing birds and wildlife, including a good number of crocodiles. Despite the enormous amount of water, the river flows slowly with little height to lose between when it emerges from the mountains and reaches the sea. It frequently backtracks to form lagoons, small lakes and swamps. The traditional culture is fascinating and each village seems to have its particular style of artistic expression. The villages of Angoram, Pagwi and Timbunke are the only ones on the river accessible by road, from Wewak. Dugout canoe trips up the river are offered by Diversion Dive Travel . For greater comfort, the same company also offers riverboat cruises. Boat cruises are also available from Melanesian Tourist Services . Larger vessels generally have to travel in the wet season, when the water level rises significantly, usually peaking around the time of Easter. Major floods are fairly common (about once every ten years) and, while the people have learned to adapt to them, cholera and dysentery can occur.
- Yam. This root crop is central to the culture of the Sepik area and farmers compete to see who can produce the largest yams. There is considerable ritual attached to the planting and cultivation of yams, involving strict rules of diet, sexual abstinence and ritual cleansing.
- Sago. This flour like substance is harvested from the pulp of a Sago tree. It is mixed with water and then either steamed or fried into a pancake like dish. Sago is a strong element of Sepik culture and witnessing a Sago tree being harvested is well worth the walk into the swamp. If you're really brave, you can try eating one of the giant Sago Grubs that live in the tree.