Windmill Observatory
On the north side of Oshima Island stands a windmill with a sheltered observation area and views of the Genkai Sea. The hills near the windmill are covered with cosmos flowers in late summer and with silvery pampas grass in fall. There is a small horse ranch near the windmill, where visitors can book riding tours of the area.
Windmill Observatory is less than 10 minutes on foot from the ruins of a World War II artillery battery and observation station. Visitors can rent bicycles to get to Windmill Observatory or take a loop bus from the ferry port, which stops at most sightseeing spots on the island.
The windmill is a stop on one of the Kyushu Olle hiking courses. The Kyushu Olle is a series of hiking routes across Kyushu, each of which can be covered in a day. The courses are well-marked with signs and colored ribbons. The Oshima course is just over 11 kilometers long and takes around 4–5 hours to complete.