A ringwork is a form of fortified defensive structure, usually circular or oval in shape. Ringworks are essentially motte-and-bailey castles minus the motte. Defences were usually earthworks in the form of a ditch and bank surrounding the site. Ringworks originated in Germany in the 10th century as an early form of medieval castle and at first wer... Found on http://en.wikipedia.org/wiki/Ringwork
A type of circular earthwork consisting of rampart and external ditch broken by an entrance. Constructed mainly by the Normans in Britain. Romanesque In England called Norman, a style of architecture influenced by the Roman. Current in the eleventh to twelfth centuries. Some Anglo-Saxon architecture is called, misleadingly, pre-Conquest Romanesque.... Found on https://www.encyclo.co.uk/local/20434