Reduit

By Crusader1307

A Reduit is a fortified structure (similar to a Citadel or Keep), used  for defensive forces to fall back to when a breach of the basic perimeter defenses occur. The term can also be applied to a line or emplacements of fortifications (in mountainous regions), to form a defensive or offensive line against an enemies approach. Reduit's were always made of stone and had one principle entrance only (no exit). Reinforced windows were added (arrow slits etc). No towers were added and they had an enclosed roof.