This area of unreclaimed marshland supports many plants and animals, including rarities such as the crested buckler fern, rare moths and spiders, and some of Britain's rarest aquatic insects.
In open fens, reed, sedge and marsh hay are still harvested, mainly for the thatching industry.
The Romans first exploited the rich peat beds of the area for fuel, and in the Middle Ages the local monasteries began to excavate the "turbaries" (peat diggings) as a business, selling fuel to Norwich and Yarmouth.