Siegniew Lakes is a fauna reserve, established on November 17, 1988.It covers an area of 23.08 hectares, of which 10.4 hectares is forest, while 12.68 hectares is the waters of two mid-forest lakes. The purpose of protection is to preserve in a natural state a sanctuary of water and songbirds, as well as aquatic, rushes and forest vegetation. The lakes are shallow, so the vegetation has excellent conditions for development. Rare plant species such as Cladium paniculata and protected species such as juniper fork and common anemone can be found here. A number of interesting bird species have their breeding places, including crane, tufted warbler, red-breasted grebe, great crested grebe, bittern, marsh harrier and grebe. In turn, the white-tailed eagle and black stork fly in for feeding. In addition, amphibians, reptiles and mammals listed in the Polish Red Book of Animals also live here: great crested newt, fire-bellied toad and otter. The waters of the lakes are characterized by high purity, thanks to which crayfish and many species of fish are found here, including tench, bream, roach, carp, pike and perch.
For amateurs of avifauna and more, a 2 km long forest nature trail has been marked out. A parking lot with a place for a bonfire was located in the vicinity. On the eastern side of the reserve there is also a blue Moraine Hills Trail from Mieszkowice through Siegieniewskie Lakes towards Moryn.