Completed in 1611, Saga Castle was actually an upgrade of the even older Muranaka Castle, sitting in a strategic position on the plains. Originally the main castle enclosure measured 126m from east to west and 122m from north to south, with 9m high stone walls, a large moat and a five-tier castle tower in the northwest corner. However the castle has been burnt down and reconstructed many times, and it also suffered damage in the Saga Rebellion of 1874. At the Shachi no Mon (Killer Whale Gate) bullet holes from the uprising are still visible.

Explore the moat and beautiful grounds, which have all been incorporated into the Prefectural Saga Castle Park.