Duncannon South Martello Tower was built about 1813 with a single 24-pdr mounted on the roof. The Martello Tower is believed to have been used by the military until at least the 1870s. It provided defences on the ridge overlook Duncannon Fort. Duncannon South Martello Tower lies on the same ridge as Duncannon North Martello which stands some 500metres away. Duncannon Fort stands some 550 metres to the South West.
Duncannon South Martello Tower was built about 1813 with a single 24-pdr mounted on the roof. The Martello Tower is believed to have been used by the military until at least the 1870s. It provided defences on the ridge overlook Duncannon Fort. Duncannon South Martello Tower lies on the same ridge as Duncannon North Martello which stands some 500metres away. Duncannon Fort stands some 550 metres to the South West.