Where were castles usually built?

Castles were usually built on elevated ground, such as hills or cliffs, to provide a defensive advantage. This allowed the castle's defenders to have a clear view of the surrounding area and to spot approaching enemies. Castles were also often built near water sources, such as rivers or lakes, to ensure a reliable supply of water for the castle's inhabitants. Additionally, castles were sometimes built in strategic locations, such as crossroads or mountain passes, to control trade and travel routes.