The Hobart coastal defences are a network of now defunct coastal batteries, some of which are inter-linked with tunnels, that were designed and built by British colonial authorities in the nineteenth century to protect the city of Hobart, Tasmania, from attack by enemy warships. During the nineteenth century, the port of Hobart Town was a vital re-supply stop for international shipping and trade, and therefore a major freight hub for the British Empire. As such, it was considered vital that the colony be protected.