South and North Caponiers
A caponier was a detached and concealed defensive structure which projected from the scarp or inner face of a ditch surrounding a redoubt or fort. It was designed to provide defence against attacking infantry by laying down flanking machine gun and rifle fire along the ditch through the openings in the caponier's walls. The Lei Yue Mun Redoubt had three caponiers on its north, south and north-west faces. Covered tunnels from the caponiers led to the interior of the Redoubt itself.