A hinged or sliding door in a floor, roof, or ceiling.
A hinged or sliding door in a floor or ceiling
A thin, human-constructed barrier which separates two pieces of land or a house perimeter
A guard over each wheel of a motor vehicle, for example, that is shaped and positioned so as to block…
A movable barrier in a fence or wall.
A structure that can be swung, drawn, or lowered to block an entrance or a passageway.