Within this park, there's not much of the old Hagi-jō to see, apart from the castle's typically imposing outer walls and the surrounding carp-filled moat. The castle was built in 1604 and dismantled in 1874 following the Meiji Restoration. The inner grounds hold a pleasant park, with spring cherry blossoms; the Shizuki-yama-jinja; the mid-19th-century Hanano-e Tea House; and other buildings, including a nagaya (Japanese long house) known as Asa Mōri House.
From the castle ruins, you can climb the hillside to the 143m peak of Shizuki-yama.