The Piast Canal (Kaiserfahrt, Kanał Piastowski) is a canal that connects the Oder Lagoon with the Baltic Sea, more exactly with the northern part of the Świna river. The eastern part of the river is bypassed, providing a more convenient south-north connection for large ships.
The canal, approximately 12 km long and ten metres deep, was dug by the German Empire between 1874 and 1880, during the reign of the first Kaiser Wilhelm (1797-1888). Thus it was not named after his grandson Kaiser Wilhelm II (1859-1941) which was famous for his interest in seafaring and battleships. Baptized as Kaiserfahrt (Emperor Way), the canal allows ships from the Baltic Sea to reach the industrial city of Stettin (Szczecin) more easily.
After the canal was opened, the town of Swinemünde (Świnoujście) began to diminish in importance as a German harbour. Another side effect was that the eastern part of the island Usedom was out off, creating an island that was name after its largest village, Kaseburg (Karsibor).
After 1945, the area was put under Polish administration, and the canal was named after the Piast dynasty.