Charles Fort Military Fortress is a 17th century star shaped military fortress that was constructed between 1677 and 1682, during the reign of King Charles II, to protect the town and harbour of Kinsale in County Cork. William Robinson, architect of the Royal Hospital in Kilmainham Dublin, and Superintendent of Fortifications, is credited with designing the fort.

As one of the largest military forts in the country, Charles Fort Military Fortress has been associated with some of the most momentous events in Irish history. These include the Williamite War in 1690 and the Irish Civil War of 1922 to 1923. Charles Fort Military Fortress remained garrisoned by the British army until 1922.

Visitors are advised to wear suitable footwear due to the uneven terrain and children must be accompanied at all times. Language guides are available and a language guide book is also available in English, Irish, French, German, Italian, Spanish, Polish and Dutch.

The view from the walls and ramparts at Charles Fort Military Fortress looking out over Kinsale Harbour is spectacular.