Zakimi Castle Ruins

Zakimi is the smallest of the World Heritage gusuku and the one built by the man generally regarded as the best military engineer the Ryukyu kingdom produced. Gosamaru constructed it in the 1420s on a hill in Yomitan, reusing stone from an earlier castle he had dismantled, and the two arched gateways here are the oldest surviving stone arches in Okinawa.

The walls curve rather than run straight — a continuous serpentine line following the contour — which is what people come to photograph. You can walk on top of them. It is free, has no gate and no closing time, sits on a rise with views over most of Yomitan, and takes half an hour. The pottery village is ten minutes away, which makes the two a natural pair.