Charles Fort is a badass military fortress in Ireland that has seen some serious action over the centuries. It's like a star-shaped stronghold that stood strong during the Williamite Wars and even survived a 13-day siege. Designed by architect William Robinson, this place is massive and well-preserved, with outer defenses towering at 16 meters high. The views from the ramparts overlooking Kinsale Harbour are absolutely stunning. Plus, it's got a cool history of being burned out by anti-Treaty forces in the 1920s. So, if you're into epic fortresses with a side of Irish history, Charles Fort is definitely worth checking out.