Bung Boraphet is the largest freshwater swamp in Thailand. It has an area of around 212 square kilometres. It covers parts of Amphoe Muang, Amphoe Tha Tako and Amphoe Chum Saeng. In the past Bung Boraphet was called the northern sea or Chom Bung as there was an abundance of aquatic animals and plants. According to surveys, there are still some 148 species of animals and 44 species of plants here. Rare animals include white-eyed river-martin and tiger perch.