The Raven

The Raven, also known as the Great Tyanian Mire, is the largest system of swampland in the world. It is located between the Kingdoms of Edierne and Magiore, and the Principality of Attalan. The Raven spans an area of roughly 7.500 km2, mostly consisting of peat bogs and marshes. It is home to a number of animals, insects, and monsters not found in many other places and the Raven is known to be an inhospitable nightmare to traverse, especially during spring and summer, when bloodflies and toads carrying Frogspawn are rampant. 
During fall, the swamps and wetlands overflow, making it nearly impossible to traverse by foot, and in the wintertime, the bogs become covered in blackish freeze, making it impossible to know where to step safely.