Jezerní slať, Natural monument in Šumava National Park, Czech Republic

Jezerní slať is a peat bog landscape in Šumava National Park located between two settlements in South Bohemia. The terrain spans low-lying wetlands and mixed plant communities across a 208-hectare area at elevations between 1057 and 1075 meters.

Protection began in 1933, when a 34-hectare zone was declared a reserve; in the 19th and 20th centuries the right-hand part of the bog had been drained and partly cut for peat, and the absence of dwarf pine in some sections still shows this. In 1973 the protected area was enlarged to 103.5 hectares and a two-storey lookout tower with a 600-metre boardwalk and nature trail was built. The nature monument was abolished on 15 January 2017 and the site is now protected as zone I of Šumava National Park.

The name Jezerní slať ("Lake Moor") comes from a small pond of 292 m² that survives in the northwest corner of the bog, now largely overgrown with peat moss. The German name is Seefilz. Visitors can follow the nature trail along the wooden boardwalk and see the dwarf birch, which grows no taller than 50 cm.

Access is easiest from the tourist car park on road II/169 between Kvilda and Horská Kvilda, from where a short approach path leads to a 120-metre boardwalk. A wooden lookout tower at the bog's edge gives a view over the whole moor with the Antýgl peak behind. Visits are not possible in winter.

The intact northwestern part holds peat up to 7.6 metres thick, while the average is 2.5 metres. A small pond of 292 square metres survives there, giving the moor its name; most of the original lake is now overgrown with peat moss.