MEDIEVAL CASTLE:
MEDIEVAL castles were built from the 11th century CE for rulers to demonstrate their wealth and power to the local populace, to provide a place of defence and safe retreat in the case of attack, defend strategically important sites like river crossings, passages through hills, mountains and frontiers, and as a place of residence. Whether a permanent home for a local lord or a temporary one for a ruler embarking on a tour of their kingdom, castles were converted from wood into stone and became ever more impressive structures with more and more defensive features such as round towers and fortified gates.
A good location for a castle was on a natural rise, near a cliff, on the bend of a river, or where older fortifications such as Roman walls could be usefully reused. Castles needed their own water and food supplies and usually a permanent defensive force, additional factors to be considered when choosing a location.