Jezerní slať is an extensive peat bog and natural landmark situated in in the Prachatice district in Šumava and part of Šumava National Park. Located between settlements Kvilda and Horská Kvilda, the average depth of the peat is around 2,5 meters. The reservation extends in the elevation from 1057 to 1075 meters. Being the fourth biggest bog in Šumava, the expanse of the area is about 208 hectares. There is a nature trail leading to the entrance of the area and also 7-meters high lookout that offers spectacular views at the whole peat bog. The trail is intended only for walking, the entrance of the cyclists is forbidden.
The area is characteristic for its climate. Large rainfall and a low temperature throughout the year, that it what makes it one of the coldest places in the Czech Republic. There are also lots of cryophilous species of plants, insects and animals, for example Vipera berus or Viviparous lizard. There are also many endangered species of plants, for example Eriophorum or Pinus Mugo, and animals, for example Eurasian lynx or Northern birch mouse.