Černý rybník, Nature reserve in Klíny, Czech Republic.

Cerny rybnik is a protected area centered on a large pond surrounded by an extensive peat bog covering roughly 13 hectares. The site sits at around 810 meters elevation near Flajska nadrz and provides habitat for plants and animals adapted to wetland conditions.

The pond was created in 1848 as a trout pond under the German name Forellenteich. The reserve itself was declared by the Most district office on 8 November 1993 to protect a peat bog 13 hectares in size with peat 1.7 to 7 metres deep. Late 20th-century finds in the bog included remains of square wooden pile structures about 9 metres long and 5 metres wide, dated to roughly 3000 BC, along with curved horns, small clay lamps, pottery and stone axes.

The pond's German name Forellenteich (Trout Pond) recalls its founding in 1848 for fish farming. A small memorial between the western bank and the road honours Jaroslav Lafka, a forestry school master from Fláje who died here in 1962.

The area can be reached on foot, by bicycle, or by car, with marked trails connecting different sections of the protected site. Bring sturdy footwear and moisture-resistant clothing, as the terrain is boggy and often wet.

In the late 20th century, remains of wooden piles from around 3000 BC were found in the bog: rectangular structures 9 m long and 5 m wide, accompanied by curved horns, small clay lamps and ceramic vessels, plus stone axes apparently from the Neolithic.