1) Alkaline ecosystems 2) Bad drainage areas 3) Boggy areas 4) Boggy biomes 5) Boggy lands 6) Boggy marshlands 7) Boggy places 8) Boggy sites 9) Boggy, swampy places 10) Bogs 11) Boston park with The 12) Flat area of East Anglia 13) Low beaty places 14) Low peaty areas 15) Low peaty lands 16) Low wetlands Found on https://www.crosswordclues.com/clue/fens
natural region of about 15,500 sq mi (40,100 sq km) of reclaimed marshland in eastern England, extending north to south between Lincoln and ... [4 related articles] Found on http://www.britannica.com/eb/a-z/f/17