Kawazu Nanataki Loop Bridge (Nanataki Viaduct): 720 degree loop bridge in Shizuoka Prefecture │ Shizuoka Japan

We would like to introduce you to Kawazu Nanataki Loop Bridge, a place where Shizuoka Prefecture’s beautiful natural scenery and innovative architecture are fused.

This bridge is a unique structure with a 720-degree loop, and its official name is the Nanataki Viaduct.

In this article, we will explore its characteristics, construction history, and award-winning history in detail.


Overview of “Kawazu Nanataki Loop Bridge”

Kawazu Nanadaru Loop Bridge is a 720-degree loop bridge located in Kawazu Town, Shizuoka Prefecture, and its official name is Nanadaru Koukakyo.

This bridge is a double loop bridge with a total length of 1064 meters, a height difference of 45 meters, and a diameter of 80 meters.

It was designed by the Japan Structural Bridge Research Institute and is supported by six piers. The loop bridge section consists of four continuous curved box girders spanning three spans.

Vehicles that can pass and speed limits

The Kawazu Nanataki Loop Bridge loops 720 degrees twice, going counterclockwise uphill from Shimoda City and Kawazu Station, and clockwise downhill from Izu City and Amagi Tunnel.

There is two-way traffic with one lane in each direction, the speed limit is 40km/h, and overtaking is prohibited. Cars, motorcycles, and bicycles can pass through.

Construction history

The Kawazu Nanataki Loop Bridge is an interesting landmark due to its construction history.

The impact of earthquakes is deeply involved in the creation of this unique bridge.

In the past, the main local road, the Shuzenji-Shimoda Line (Shizuoka Prefectural Road No. 13), twisted along the mountain, but due to the 1978 earthquake near Izu Oshima, the mountainside road collapsed.

Drawing on the lessons learned from this earthquake, construction began using a new construction method with the aim of making it easier to access and preventing landslides caused by earthquakes.
Then, in 1981 (Showa 56), the Kawazu Nanataki Loop Bridge was completed.

That year, this unique loop bridge won the Tanaka Award from the Japan Society of Civil Engineers, and its fame spread.

This award recognizes its innovative design and outstanding example of earthquake safety measures, and is evidence of the high level of technology behind the bridge’s construction.

As a unique structure born from the effects of an earthquake, the Kawazu Nanataki Loop Bridge offers visitors an opportunity to learn about its history and the engineering advances behind it.

Basic information about “Kawazu Nanataki Loop Bridge”

InfoKawazu Nanadaru Loop Bridge
 Official name: Nanadaru Koukakyo
 Nashimoto, Kawazu-cho, Kamo-gun,
 Shizuoka Prefecture
Parking lot
 Parking available
 (just under the loop bridge)

Restaurant search/reservation

Surrounding touring spots

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