A number of coastal fortifications were built in County Cork, Ireland, to defend the county's coastline, and in particular the strategic berths at Cork Harbour, Kinsale Harbour, Berehaven and Bantry Bay. The fortifications initially included medieval tower houses built to defend strategic points (14th-17th centuries), subsequent Martello towers designed to counter threatened French invasion (18th-19th centuries), and later Palmerston Forts to further improve coastal defence (19th century). The latter were subsequently updated with longer-range coastal artillery - to support the naval defence of the "Western Approaches" during the First World War (early 20th century).