Unkai, the Autumn Sea of Clouds & Tsuwano Castle in the Sky

Unkai literally means “Sea of Clouds.”
This natural phenomenon occurs when there is a large difference between daytime and nighttime temperatures, creating thick layers of fog or clouds that settle in the valleys.

From the top, it looks as if Tsuwano Castle is floating on a vast ocean of clouds — a breathtaking “Castle in the Sky.”

While this magical view can sometimes be seen in spring, it appears most frequently in autumn.
During this special season (usually from late October to the end of November), the chairlift to the Tsuwano Castle Ruins opens early at 7:00 a.m. on weekends and public holidays, giving lucky visitors the chance to witness the sea of clouds until around 8:00 a.m.

In addition to the unkai, the castle grounds are surrounded by bright red maples and golden ginkgo trees, offering one of the best spots to enjoy Tsuwano’s autumn beauty.

Tsuwano Castle Ruins can also be reached on foot from the Taikodani Inari Jinja Shrine parking area by following the 1.5 km Chugoku Nature Trail.
This walk takes about 40 minutes uphill to the Demaru outer fortress, followed by another 20 minutes to the Honmaru main keep.

Overall, it’s a relatively easy and enjoyable climb.

For more information about the chairlift during the unkai season,
please contact the Tsuwano Tourism Association.

Back to the MAIN MENU of Diving Deeper