List of coastal fortifications of County Cork
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, subsequent Martello towers designed to counter threatened French invasion, and later Palmerston Forts to further improve coastal defence. The latter were subsequently updated with longer-range coastal artillery - to support the naval defence of the "Western Approaches" during the First World War.
Cork Harbour
As one of the world's largest natural harbours, Cork Harbour's defences were built from medieval times up to the 20th century to defend the Port of Cork, Haulbowline naval yards, and Naval Air Station at Queenstown. Some of these defences were tested during the Siege of Cork and Fenian Rising - the harbour remains the home-port of the Irish Naval Service.Kinsale Harbour and approaches
From medieval times, the harbour and berths at Kinsale were of strategic importance, and its defences were tested during the Battle of Kinsale and Williamite War. Though declining in importance in the 18th and 19th centuries, several structures were in use until they were burned during the Irish Civil War.| Name | Location | Type | Image | Era | Coordinates | Notes |
| Charles Fort | Kinsale | Coastal star fort | 16th century 17th century | Though internals were burned-out during the Civil War, key structures are intact and operated by the OPW as a heritage tourism site | ||
| James Fort | Kinsale | Pentagonal fort | 16th and 17th century | Damaged during the Williamite War and later left to ruin. Open to public. | ||
| Ringrone Castle | River Bandon | Tower house | 13th century | Built by the de Courcy family. Now a complete ruin | ||
| Old Head Castle | Old Head of Kinsale | Tower house | 13th century | Another de Courcy castle built in defence of the Kinsale coast. Only some walls remain A nearby signal tower has since been restored. |
Bantry Bay and Berehaven Harbour
The deep-water berths at Bantry Bay and Berehaven Harbour were important from as early as the Nine Years' War and Siege of Dunboy in 1602, through the United Irishmen Rebellion and French Armada landings in the 1790s. The defences remained critical to support the Bantry Bay Naval Air Station during World War 1, and Berehaven "Treaty Port" was used by the Royal Navy fleet until it was relinquished in 1938 under the terms of the Anglo-Irish Treaty.| Name | Location | Type | Image | Era | Coordinates | Notes |
| Dunboy Castle | Beara Peninsula | Castle | 15th or 16th century | An O'Sullivan Bere castle built to defend Bantry Bay and Berehaven harbour. Ruined since the Siege of Dunboy | ||
| Martello towers | Garnish Island, Whiddy Island, Bere Island | Martello towers | 19th century | Garinish: Whiddy: Bere: | Built to defend the deep water berths of Bantry Bay, four towers were built on Bere Island, with others on Whiddy and Garnish. |
Baltimore and Roaring Water Bay
The defences at Baltimore, Roaring Water Bay and surrounding islands were largely built by landed families from the 14th to 17th centuries. Some were relinquished after the Nine Years' War and involved in the Sack of Baltimore.| Name | Location | Type | Image | Era | Coordinates | Notes |
| Dún na Séad | Baltimore, County Cork | Tower house | 14th to 17th century | Built on an earlier Anglo-Norman structure, Dún na Séad castle was an O'Driscoll stronghold | ||
| Dún na Long and Dún an Óir Castles | Cléire and Sherkin Islands | Tower houses | 15th to 17th century | Sherkin: Cléire: | Built by the O'Driscolls in the same period as the island's friary, Sherkin's Dún na Long and Cléire's Dún an Óir were intended to defend the approaches to Baltimore and Roaring Water Bay |