The protected area Rokytská Slať (Rokyta Fen) was established in the large peat-bog about 5 km west of the village Modrava.

The reserve is 104 ha large and it stretches across the whole peat-bog, which is 142 ha large. The supplies of peat are estimated to 3 million cubic metres. The peat layer is 1.5 - 2.3 m thick. Most of vegetation comprise spruces and mountain pines. The so-called "dead forest" can be seen there - the withered trunks of trees, which are white from sun, without roots and with skeleton-like appearance.

The peat-bog lies on the upper reaches of the Roklanský Potok (Roklan Stream) in the Zone I of the National Park Šumava and it is not open to the public.
The red marked path, which runs from Modrava to the small village Prášily and to the town Železná Ruda, leads along the border of the protected area (about 1.5 km).