A castle is a massive, permanent fortification designed for defense and residential purposes. Architecturally, these structures were engineered using local stone and timber, employing complex systems of defensive measures to withstand prolonged sieges. Key structural components include curtain walls, which delineate the perimeter, and towers, which provide elevated vantage points for observation and defense. Defensive engineering principles were incorporated through multiple layers of enclosure, often featuring advanced gatehouses, moats, and crenelated battlements. The layout and function of a castle reflected advanced understanding of military logistics, defensive positioning, and structural stress management, evolving over time to incorporate greater resilience against evolving forms of siege weaponry.