The ÃÂepkeliai Marsh () is the largest bog (a mire) in Lithuania. Located in VarÃÂna District Municipality, south of Marcinkonys village and north of Kotra River, which flows along the BelarusâÂÂLithuania border in this area. Its area is a nature reserve and a Ramsar site.
The area of the swamp is protected as a state nature reserve (ÃÂepkÃÂliai Reserve), with its administration in Marcinkonys, and part of the cross-border wetlands of international importance: Kotra-Cepkeliai Transboundary Ramsar Site established in 2010. It consists of the Kotra Ramsar site in Belarus (designated in 2002) and the ÃÂepkeliai Mire Ramsar site in Lithuania (designated in 1993). In 2011 the ÃÂepkeliai Nature Reserve together with Dzà «kija National Park were certified as PAN parks.
The bog itself covers an area of , while the larger area of which also includes some neighboring sections of the Dainava Forest is declared as the ÃÂepkeliai Nature Reserve. It was created in 1975, and is protected since 1960 (initially as a botanical-zoological sanctuary). It is also part of Natura 2000, the European ecological network.
Most of ÃÂepkeliai is a raised bog while there are some smaller areas of a fen and flooded forests. There are 21 small bog lakes in the area, some of them are Glacial Age relicts, remnants of larger lakes that have been swamped. The largest of them is the . A peat stratum is of 5âÂÂ6 meters of thickness.
It grows a lot of cranberries, wild rosemaries, heather. The reserve is a sanctuary for cranes, white-tailed eagles, black grouses, heather cocks, mountain hares, martens, smooth snakes.
The ÃÂepkeliai Marsh is closed for visiting, except from the observation tower and an educational trail by the edge of the marsh south to Marcinkonys village. The track was closed since June 2021. Cranberry and mushroom picking is allowed for 10 days in early September for residents of the nearby villages with a permit, for personal use only.
The name ÃÂepkeliai comes from a personal name , i. e. ÃÂepkáuskas, ÃÂepkẽviÃÂius, , , which is a form of name Szczepan. As at the beginning of 20th century, this name was used only for small western part of the bog. The main part was called ("Russian woodland") in Slavic maps. Local Lithuanian name for this swampy and forested region was Gudo à  alis ("The Land of Gud").