Castle Surrounded By Water

There is a further distinction between:
Water castles, that are protected by artificial water-filled moats or ponds (man-made defences)
Water castles, whose primary means of protection is from river courses or which stand on islands in a lake or natural pond (natural defences).
In all cases, water is used as an obstacle to hinder an attacker. That apart, an abundant supply of water was also an advantage during a siege. Such a castle usually had only one entrance, which was via a drawbridge and that could be raised for protection in the event of an attack. To some extent these water castles had a fortress-like character.