abatis advanced work antenna tower balistraria bank banquette barbed-wire entanglement barricade barrier bartizan bastion battlement belfry bell tower breastwork bulwark campanile casemate cheval-de-frise circumvallation colossus column contravallation counterscarp cupola curtain demibastion derrick dike dome drawbridge earthwork enclosure entanglement escarp escarpment fence fieldwork fire tower fortalice fortification glacis lantern lighthouse loophole lunette machicolation mantelet martello martello tower mast merlon minaret monument mound obelisk observation tower outwork pagoda palisade parados parapet pilaster pillar pinnacle pole portcullis postern gate pylon pyramid rampart ravelin redan redoubt sally port scarp sconce shaft skyscraper spire standpipe steeple stockade stupa television mast tenaille tope tour tower turret vallation vallum water tower windmill tower work