Rosnowskie Lake, commonly known as Rosnowo, is one of the oldest Polish retention reservoirs. It was created in 1922 as a result of damming the Radew River with an earth dam. It has an area of 190 hectares and is one of the deep lakes (the maximum depth of the reservoir is as much as 12 meters). Rosnowo is a trough-shaped, longitudinal flowing reservoir, running east-west, 10km long and 400m wide. The lake is mainly used for power generation, flood control and has a recreational function.
Surrounded by forests, with high shores and many coves, it is a great base for anglers. The waters of Rosnow are home to such fish as roach, perch, pike, tench, bream, catfish, carp, crucian carp and bleak. You can also meet brook and rainbow trout, zander and even burbot and chub. As an interesting fact, it is worth mentioning that since 1974 as many as 40 medal fish specimens, caught in Rosnow, have been reported to angling magazines, which is proof of the incredible richness of the lake's fauna and encourages people to visit. To get to the stands prepared by the host of the water, from route 165 Koszalin - Bobolice head for Zegrze Pomorskie, after 2km turn left into a forest road, where you will see PZW signposts. The road leads to the square where anglers gather before the competition and you can leave your car there, access to the stands is easy and marked. In the period from April 1 to September 30, the use of diesel-powered watercraft is prohibited on the lake.