Charles Fort, Military fort in Kinsale, Ireland.

Charles Fort is a pentagonal military structure in Kinsale that spreads across roughly eight hectares, featuring five bastions named Kinsale, Charles, Cockpit, Flagstaff, and North. The design allowed defenders to cover every approach from both the water and the surrounding land.

Charles Fort was built between 1677 and 1682 on the site of Ringcurran Castle, which had featured in the 1601 Siege of Kinsale. Designed by surveyor-general Sir William Robinson and named after Charles II, it was besieged for thirteen days in 1690 during the Williamite War, when John Churchill, then Earl of Marlborough, captured Kinsale and its forts. Repairs followed, and the fort served as a British Army barracks until 1921.

The Irish name Dún Chathail ties the fort to Charles II, and the site is run by the Office of Public Works as a heritage attraction. Its five bastions carry individual names: Kinsale (also called the Devil's), Charles, Cockpit, Flagstaff and North. The commander's quarters now hold an exhibition space.

The grounds are straightforward to walk around, and the waterfront offers good viewing points across Kinsale Harbor, especially on clear days. Allow several hours to explore the five bastions, ruins, and cannons scattered throughout the site.

The fort's five bastions carry individual names: Kinsale (also called the Devil's), Charles, Cockpit, Flagstaff and North. The two seaward bastions, Kinsale and Charles, were built heavier than the rest because attack was expected from the water, while the landward sides sit below higher ground.