A wonder of modern architectural engineering, the 13-kilometer Seto Ohashi Bridge connects Okayama Prefecture on the main island of Honshu with Kagawa Prefecture in Shikoku. The imposing structure actually consists of 10 connected two-tiered bridges; the upper deck is for cars and the lower is for trains. As such, Seto Ohashi is the world’s longest double-decked bridge. It was built over a period of 10 years, from 1978 to 1988—a painstaking process that visitors can learn more about at Seto Ohashi Memorial Park in Sakaide, at the foot of the bridge on the Shikoku side. A free museum details the challenges and triumphs of the construction project, while the 108-meter Seto Ohashi Tower offers views over the entire length of the bridge and the islands of the Seto Inland Sea on both sides of it. Driving across the bridge takes about 15 minutes, as does the train trip between Utazu Station on the Shikoku side and Kojima Station in Okayama.