The Poprad (also known as the Popper in German, or Poprád in Hungarian) is a river in Slovakia and Poland that rises in the High Tatras, flows through the town of Poprad and then flows into the Dunajec River above Stary Sącz in Poland. Of the total length of 174 km, 113 km are in Slovakia, 31.1 km form the border between Slovakia and Poland and 30.9 km are in Poland. The Poprad's catchment area is the Upper Spiš.
It is the only major river in Slovakia that flows into the Baltic Sea, so that the European watershed in this area leaves the main ridge of the Carpathians and runs across the Spiš.
The river is formed by the confluence of the Hincov potok (Hinzenbach in German) and Krupá streams in the Mengusovská dolina (Mengsdorfer Tal in German). The source of the Hincov potok (considered the main source of the Poprad) is the glacial lake Veľké Hincovo pleso (German: Great Hinzensee), which is located in the High Tatras at 1,965 metres above sea level. The source of the Krupá, on the other hand, is the glacial lake Popradské pleso (German: Poppersee) (Wikipedia).