There are several kinds of moats: water moat, karabori (dry moat), unejo tatebori (a series of parallel trenches running up the sides of the excavated mountain), and the earthen wall, which was also called doi, was an outer wall made of earth dug out from a moat.
堀は水堀の他、空堀、畝状竪堀などの形態があり、土塁は土居（どい）ともいい、堀を掘った土を盛って外壁とするものである。