Sejny [ˈsɛi̯nɨ], (Lithuanian: Seinai) is a town in north-eastern Poland, in Podlaskie Voivodeship, close to the border with Lithuania and Belarus. It is located in the eastern part of the Suwałki Lake Area (Pojezierze suwalskie), on the Marycha river, being a tributary of Czarna Hańcza. As of 1999 it had almost 6,500 permanent inhabitants, with many more inhabiting the area in the tourist season, and was the capital of a separate powiat.