Kanał Grunwaldzki is a narrow waterway in the Masurian Lake District that links Lake Kotek to Lake Tałtowisko and runs for approximately 470 meters. The canal has reinforced concrete banks and maintains a depth of around 1.8 meters, making it passable for small recreational boats.

The canal was built between 1765 and 1772 as part of early infrastructure development in the Masurian region. This construction project connected two separate lakes through deliberate engineering during a period of regional expansion.

The waterway forms part of the protected Masurian Lake District landscape, supporting local fishing activities with populations of perch, pike, and eel.

A road bridge crosses the canal near the lakeshore and provides the main connection between the Ryn and Mikołajki areas. The waterway is easily visible from the road, though parking space near the canal is limited.

The canal underwent an 11 million złoty modernization project that included deepening operations and the installation of wildlife crossings along its banks.