A class of sites in places like Thailand, Cambodia, England, Ireland, and Flanders. In the first two, they are known from protohistoric and early historic sites and are settlements encircled by one or more irregular moats. In England, Ireland, and Flanders, they were built during the late medieval period. There was a tradition of building defensive moats around castles and manorial establishments and it was taken up by wealthy farmers later. In marshy areas, a moat provided an extra means of drainage when the climate was deteriorating and acted as a source of both dry-season water and edible aquatic flora and fauna.