Kaichu Doro, often translated as the “Underwater Road,” is one of Okinawa’s most scenic driving routes. Stretching for approximately 5.2 kilometers, it connects the Katsuren Peninsula on Okinawa Island with Henza Island.
Despite its name, the road does not actually run underwater. Instead, it is built on a raised embankment extending across the shallow sea. Unlike a conventional bridge, this unique structure allows drivers and passengers to look out across the water from almost the same height as the sea surface.
Kaichu Doro is a remarkably straight, four-lane road and has become one of the iconic roads of Okinawa. On both sides, shallow emerald-green waters stretch toward the horizon, creating the sensation of driving directly across the sea.
The route was originally constructed as an industrial road, but its spectacular scenery has made it a popular leisure destination. The combination of a straight road, open ocean, and distant islands makes the drive especially enjoyable on a clear day.
Because the road is built on an embankment rather than a high bridge, the surrounding sea remains remarkably close to eye level. This gives travelers a unique perspective that is quite different from driving across a conventional bridge.
Kaichu Doro forms the first part of a popular island-hopping drive from Okinawa Island. After crossing to Henza Island, travelers can continue onward to Miyagi Island and Ikei Island, enjoying the changing coastal scenery along the way.
The route is especially appealing to travelers who want to explore Okinawa at their own pace. Rather than simply traveling from one destination to another, the road itself becomes part of the experience.
Approximately halfway along the road is Sea Station Ayahashi-kan, a roadside park where travelers can take a break and enjoy the surrounding seascape.
The facility includes a parking area, restrooms, a road information center, a restaurant, and shower facilities. Its location beside the sea also makes it convenient for visitors enjoying marine activities in the surrounding waters.
The complex also features a Marine Culture Museum and a local shop selling traditional handicrafts, Okinawan souvenirs, and products such as mats woven from igusa rush.
Construction of Kaichu Doro began in 1971, and the road opened the following year as a two-lane route. As traffic and its importance as a transportation link increased, the road was expanded to four lanes, with the widening completed in 1999.
A roadside park was also developed around the same time. Bridges used to maintain the circulation of seawater beneath the road were replaced with longer structures, helping preserve the flow of the surrounding shallow waters.
Kaichu Doro is more than a practical road connecting Okinawa Island with the nearby islands. Its unique construction, shallow turquoise waters, and uninterrupted ocean views have transformed it into one of the most memorable driving experiences in central Okinawa.
For travelers exploring the Katsuren Peninsula and the surrounding islands, driving along Kaichu Doro is an unforgettable way to experience the beauty of Okinawa’s tropical sea—literally with the ocean stretching out on both sides of the road.
140 minutes by bus from Naha Bus Terminal