What traditional Japanese gate is located in front of one of the castle gates?
Iha Castle:  The Okinawa Prefectural government erected a stone Torii in front of one of the castle gates, along with a plaque describing it. Torii: A torii (鳥居 ) is a traditional Japanese gate most commonly found at the entrance of or within a Shinto shrine, where it symbolically marks the transition from the profane to sacred.
Torii