Broad Marsh Reserve was created in 1984 and covers 77 hectares of raised bog, swamp and moist forests between Osieck and Zabieżki, south of Devil Down Reserve; a wildlife refuge. The largest area is covered by fresh forest (48.8%), moist forest (23.7%) and swamp forest (18.2%), with pine as the dominant species (86.8%). Vegetation is typical of bogs, and inaccessible areas are home to animals, amphibians and reptiles.