This is arguably the symbol of Okinawa: the gate to Shuri Castle. I was surprised to find that it's a reconstruction; the original was destroyed in the war. In any case, this is the one "must" photo from Okinawa for Japanese tourists; pretty women in Okinawan kimono loiter near the entrance to serve as for-fee models.
On a clear day, the top of the castle ruins provides a panoramic view of Naha. This was not such a day, unfortunately. The grounds also house a folkcraft museum and some workshops for bingata, Okinawa's traditional cloth dying.