The Fens or Fenlands in eastern England are a naturally marshy region supporting a rich ecology and numerous species. Most of the fens were drained centuries ago, resulting in a flat, dry, low-lying agricultural region supported by a system of drainage channels and man-made rivers and automated pumping stations. There have been unintended consequences to this reclamation, as the land level has continued to sink and the dykes have been built higher to protect it from flooding.