A beel is a wetland with static water (as opposed to moving water in rivers and canals.
Baikka Beel in the north of Bangladesh has been a sanctuary since 2003, and native swamp forest trees were planted to restore diversity. Fishing, hunting and the collection of aquatic plants is forbidden and as a result, fish are more abundant and large flocks of birds have started coming back, including species which had totally disappeared for many years.

During the monsoon, almost half the length of these trees are immersed by water.