Lake Sentani

Lake Sentani is Papua's best-known lake, spreading 28 kilometres from east to west and 19 kilometres north to south across the lowlands about 20 kilometres from the provincial capital, Jayapura. Around a hundred square kilometres of water sits ringed by the Cyclops Mountains, and dozens of small islands and inlets break up what would otherwise be a single open sheet of water. The lake's most distinctive human feature is architectural: many Sentani families still live in houses built on posts directly over the water, a tradition documented in the region for well over a century and visible today in villages scattered along the shoreline. Photographs and museum collections from the early twentieth century, including material held by the Netherlands' National Museum of World Cultures, show these pile-dwelling villages and the dugout canoes, or proas, that connect them, alongside men's ceremonial houses raised on the same style of stilts. Isolation has produced its own wildlife here too. The lake is home to fish found nowhere else on Earth, among them the Sentani rainbowfish and red rainbowfish, plus a distinct goby and gudgeon species unique to these waters. Less fortunate is the Sentani sawfish: freshwater sawfish up to three metres long were a well-documented feature of the lake as recently as the 1970s, but they have since disappeared entirely. At the lake's northwest end, the archaeological site of Doyo Lama holds megalithic stones carved with petroglyphs, which some researchers connect to prehistoric contact with Micronesia rather than mainland New Guinea traditions. Growing settlement around the shoreline has also brought a modern problem: untreated household waste draining into the lake has raised coliform bacteria levels in parts of the water. Sentani town, a short drive from Jayapura's airport, remains the easiest base for visiting the lake and its stilt villages by chartered boat.