出典:Wikipedia
出典:『Wikipedia』 (2011/06/09 15:34 UTC 版)
A moat is a deep, broad ditch, either dry or filled with water, that surrounds a castle, building or town, historically to provide it with a preliminary line of defence. In some places moats evolved into more extensive water defences, including natural or artificial lakes, dams and sluices. In later castle s the moat or water defences may be largely ornamental.