Kaichu-doro is an inter-island highway that slices through the sea in a straight line and then connects Katsuren Peninsula and Henza Island. It is a route to access Miyagi and Ikei islands. Its construction is a combination of bridges and earth dredged up from the shallow sea bottom and packed to form a roadbed. Dubbed the “road that glides across the sea” or “the beautiful bridge,” the highway has become a place famous for its delightful views.
Ikei Island, Miyagi Island and Henza Island are part of Yonashiro Town, while Hamahiga Island is part of Katsuren Town. The Kaichu-doro links the first three of these islands. Halfway across there is a rest area that includes a park, plus parking for 300 cars and the Umi no Eki Ayahashi Hall. Local vegetables, fish, souvenirs and more are for sale on the first floor of this building, located together with a restaurant featuring a great view of Kin Bay. The second floor is a cultural museum focusing on the maritime history of the Katsuren Peninsula. Here you can see models of a Yanbaru ship and a Maran vessel used in trade and coastal shipping.
Before the war, before the highway was built, people got back and forth between Katsuren and Henza using Okinawa’s traditional boats, called Sabani. After the war these gave way to larger boats and amphibious vehicles provided by the U.S. military. These vehicles churning their way through the water were the origin of the name, the “road through the sea.”
When local people packed a roadbed of earth across the shallows to make a dike road, travel time across the bay was cut dramatically. However, the dike interrupted the natural ebb and flow of the sea. Almost no seawater came into the bay and the bay’s environment deteriorated. The present road and associated facilities were built later when the national government launched public works improvements along the east coast. Now, south of the road, there is tideland and an extensive area of seaweed. Local people and tourists alike enjoy clamming, swimming and relaxing on the beach.
Among other well-known locations is Ikei Beach, located at the top of Ikei Island. From Henza Island, the Hamahiga Bridge allows you access to Hamahiga Island. Next to its serene and vivid green nature, Hamahiga offers two sacred places to visit that are said to be linked to the ancient history of the Ryukyu Islands: Amamikiyo and Shinerikiyo.