आक्रमणापासुन बचाव व्हावा म्हणुन बांधलेले किल्लासदृष्य घर वा राजवाडा.या वास्तुचा वापर राजदरबारी वा तत्कालिन श्रीमंत राहण्यासाठी करीत असत.शक्यतोवर, या वास्तुचे बांधकाम उंच जागेवर किंवा टेकडीवर/पहाडावर,आक्रमणास आणि पोचण्यास त्रासदायक अश्या जागी असे.यात आक्रमणापासुन बचावाची किंवा आक्रमण झाल्यास परतविण्याची अनेक साधने आणि युक्त्या केलेल्या असत.

A castle is a type of fortified structure built during the Middle Ages predominantly by the nobility or royalty and by military orders. Scholars usually consider a castle to be the private fortified residence of a lord or noble. This is distinct from a mansion, palace and villa, whose main purpose was exclusively for pleasance and are not primarily fortresses but may be fortified. Use of the term has varied over time and, sometimes, has also been applied to structures such as hill forts and 19th- and 20th-century homes built to resemble castles. Over the Middle Ages, when genuine castles were built, they took on a great many forms with many different features, although some, such as curtain walls, arrowslits, and portcullises, were commonplace.