Caerlaverock Castle, located in Scotland, is a cool triangular castle with a moat that was built in the 13th century. It was home to the Maxwell family until the 17th century when it was abandoned. The castle saw some action during the Wars of Scottish Independence, including a siege by the English in 1300. Despite being partially demolished and rebuilt multiple times, the castle still retains its unique triangular shape and is now a popular tourist spot.