Hyrule Castle Moat is a location from The Legend of Zelda: Breath of the Wild. As its name implies it is a large moat that surrounds Hyrule Castle in the Hyrule Field region.
Several bridges where built over it to allow people to cross over to islands such as Moat Bridge which allows access to the island where Castle Town Prison once stood. The Helmhead and Boneyard bridges allow access to Hyrule Forest Park. A raft located near the burned out husk of Castle Town Prison can be used by Link to travel through the moat itself.