Fort Eliza, also known locally as the Salt Battery is a freestanding five-sided, four-gun battery which was constructed around 1812 and is located 400 yards out Crank Road standing on the east side of the River Shannon. It was upgraded from an earthworks structure to include a moat with cut-stone walls, a drawbridge, ammunition store, guard house and platforms for four guns on revolving tracks. Three sides face the river and were formed of broad parapets while the other two sides meet at the rear salient angle at a guardhouse which is now ruined. At the centre of the enclosure was the brick-vaulted powder magazine. It was upgraded from an earthworks structure to include a moat with cut-stone walls, a drawbridge, ammunition store, guard house and platforms for four guns on revolving tracks.
The possibility of invasion by France was recognised by the authorities at the end of the eighteenth century and early nineteenth century plans were put in place for the construction of permanent defences at Banagher. The defence of crossing of the River Shannon was of strategic importance and therefore this battery is one of several Napoleonic defences which were constructed or upgraded from older buildings. Fort Eliza, Banagher Military Barracks, Cromwell’s Castle and Fanesker Tower were designed as a chain of defences to defend the Old Bridge of Banagher from all angles. The Shannon fortifications are of a special historical significance also in part to their inland location.