The Radomka is a river in central Poland and a left-bank tributary of the Vistula. It has a length of 98 km and a basin area of over 2000 km<sup>2</sup> (all in Poland). The river has its source in forests 4 km south of Przysucha, at a height of 310 meters above sea level. There is a retention reservoir, built in the valley of the Radomka in Domaniów, which has the largest surface area of any lakes in Mazowsze Voivodeship (5 â 7 km<sup>2</sup>). It is also utilised for recreation purposes.
After flowing through the hills of the Lesser Poland Upland, the Radomka enters a wide urstromtal, to finally join the Vistula near Ryczywol, at 160 meters above sea level.
The reserve, located in a forest at the source of the Radomka, was opened in 1978. It aims to preserve natural wilderness, with its fir and beech trees.