The Akashi Kaikyo Bridge is, with a length of almost four kilometers, the world's longest suspension bridge. Opened in 1998, it spans the Akashi Strait (Akashi Kaikyo) between Kobe and Awaji Island and is part of the Kobe-Awaji-Naruto Expressway, one of three expressways which connect Honshu with Shikoku.
An interesting way to experience the bridge up close is walking the Maiko Marine Promenade, a circuit of observatory walkways under the bridge's platform, about 50 meters above the water. Accessed by elevator from the base of the bridge (Kobe side), the walkways offer unique views of the bridge's interior, the Akashi Strait and Osaka Bay.
The Bridge Exhibition Center at the foot of the Kobe side of the bridge provides well-presented information about the planning and construction of the bridge and about other suspension bridges around the world, although the detailed explanations are available in Japanese only.
The Bridge Exhibition Center and the Maiko Marine Promenade are located a short walk from Maiko Station on the JR Sanyo Line (25 minutes, 310 yen from Sannomiya Station by local train) or Maiko-Koen Station on the Sanyo Railway Main Line.