The 14th century stronghold of the Hokuzan kingdom, which ruled northern Okinawa before the island was unified. What survives is 1.5 km of serpentine stone wall running along a ridge above the East China Sea, and it is the finest castle ruin in the north. Time it for late January and early February, when the cherry trees along the approach open before anywhere else in Japan. It pairs naturally with Churaumi on one northern loop.