The nature reserve was established to protect the natural values of the edge of the Postomia river valley, and covers the picturesque southern slope of Toruń-Eberswalde Glacial Valley, and the river bed and the reed of the Postomia river between Lemierzyce and Słońsk. The nature reserve is home to numerous massive old trees, among them oaks, beeches, hornbeams, elms, poplars and maples. The largest oak has a trunk with a circumference of over 600 cm. The reserve is located 2 km from the town centre of Słońsk, at the road to Głuchowo - just before the bridge over the Postomia, you will see an intersection with a dirt road leading to the nature reserve.