Kikkou Park, which includes the bridge and castle, is a popular tourist destination in Japan, particularly during the Cherry blossom festival in the spring and the autumn color change of the Japanese maples (momiji). It was declared a National Treasure in 1922.
After Iwakuni Castle was completed in 1608 by Kikkawa Hiroie, the first lord of Iwakuni Domain, a series of wooden bridges was built. However, most of them were destroyed by floods several times before the construction of the iconic Kintai Bridge. Afterwards, Kintai Bridge was built by the third lord, Kikkawa Hiroyoshi in 1673. The new stone piers replaced the old wooden ones. Though thought to be flood-proof, the bridge was destroyed by a flood the next year. As a result, the stone piers were redesigned for greater strength, and a special tax was created to maintain the bridge. This maintenance involved periodic rebuilding of the bridge: every 20 years for three spans in the middle, every 40 years for two spans connecting to the riverside. Consequently, the bridge remained undestroyed for 276 years, until washed away again by flooding from typhoon "Kijia" in 1950. It had been in a weakened state at the time, due to the fact that the Japanese had stopped maintaining the bridge during World War II, and that the year before the typhoon, a large amount of gravel was taken by the US Military Force from the river around the bridge to expand the US Marine Corps Air Station in Iwakuni, strengthening the flow of the river. In 1953, the bridge was reconstructed similarly to the original, using metal nails made from the same tatara iron as the Katana to increase its durability. Between 2001 and 2004, all five bridge girders were restored for the first time in 50 years. In 1922 the bridge was declared a national treasure.
The bridge is composed of five sequential wooden arch bridges on four stone piers as well as two of wooden piers on the dry riverbed where the bridge begin and ends. Each of the three middle spans is 35.1 meters long, while the two end spans are 34.8 meters for a total length of about 175 meters with a width of 5 meters.
For nearly three hundred years, the many versions of the bridge stood without the use of metal nails. This was achieved by the careful fitting of the wooden parts and by the construction of the thick girders by clamping and binding them together with metal belts. The main wooden parts of the bridge were covered by sheets of copper for additional durability.
The shape and weight of the bridge made it extremely strong at the top, but incredibly weak from underneath. To address concern that flood waters rushing along the river would destroy the bridge in its entirety, the bridge was designed so that the wooden pathway merely "floats" on top of its frame using mortise and tenon joints. This allowed rising flood waters to lift out the wooden pathway and carry it off down stream while sparing the main structure.
- Iwakuni Station on Sanyo Main Line
- Nishi-Iwakuni Station or Kawanishi Station on Gantoku Line
- Shin-Iwakuni Station on Sanyō Shinkansen
- From these stations, it is still necessary to take a bus or taxi.
- Iwakuni Castle - the bridge was placed as one of the gates of the castle
- Nishiki River - the bridge spans the river
|Wikimedia Commons has media related to Kintaikyo.|