The fort, Burgh Castle, stands on the estuaries of the Yare and the Waveney. It's design was changed during construction to bring it up to date with the latest military ideas. It would seem then that building was begun before the design of the complete chain of forts was decided on.

Ptolemy called the river Yare Gariennos a British name from ger meaning talking or shouting. This is no doubt the origin of the name of the fort. The Notitia Dignitatum gives Garianno and records the presence of a unit of Stablesian cavalry.