Black Lake is located in the north-western part of Olsztyn. It is one of the smaller reservoirs in the city, with an area of about 1.3ha and an average depth of 2.7m. It lies between Ukiel Lake (Jezioro Krzywe) and Long Lake (Jezrioro Długie) and also between Baltic street (ulica Bałtycka) and Sailors street (ulica Żeglarska).

It is surrounded by green areas with established hiking trails. This lake is not suitable for swimming, but it's quite high reed shores are frequently occupied by anglers. The surroundings of the lake provide the conditions for a peaceful rest on park benches or for lazy walks. It is just a few minutes walking distance from the City Beach at Ukiel Lake and from the walking and cycling paths around Long Lake. And the distance to the Old Town should not take more than 20 minutes.

It is interesting that in the 70s of the 20th century Black Lake was artificially connected by an underground channel with Long Lake, as well as by an open channel with Ukiel Lake. This was to assist in the purification of the waters of Long Lake by the waters of Ukiel Lake. Unfortunately, this method did not produce the expected results.