Saikaidō (西海道, literally, "western sea circuit") is a Japanese term for both an ancient division of the country and the main road running through the region.
Saikaidō was one of the main circuits of the Gokishichidō system. It was first established during the Asuka period. Over centuries, the government functions of the Gokishichido became less important. However, the traditional eight regions, including Saikaidō, remained cultural markers.
The Saikaidō road connected the capitals of the provinces in this region.
Historic earthquakes are named "Saikaidō" when the main damage was in the Kyūshū region. Often quakes are called by the Japanese era name along with region location such as Saikaido.
- 8th century: Dazaifu was established as a government center for the island region.
- November 24, 1899 (Meiji 32): regional disaster called the Saikaidō earthquake (西海道震 Saikaidō jishin) at Latitude: 31.9/Longitude: 132
- August 5, 1968 (Shōwa 43):regional disaster called the Saikaidō-Nankaidō earthquake (西海道南海道震 Saikaidō Nankaidō jishin) at Latitude: 33.3/Longitude: 132.2
- Nussbaum, Louis-Frédéric. (2005). " Goki-shichidō" in Japan Encyclopedia, p. 255.
- Sale, George et al. (1759). "Japan," An Universal history, from the earliest account of time, Vol. 30, p. 72.
- Nussbaum, "Dazaifu" in p. 150; Japan-guide.com, Dazaifu; retrieved 2012-2-14.
- National Oceanic and Atmospheric Administration (NOAA), National Geophysical Data Center (NGDC): NOAA/Japan: Significant Earthquake Database; retrieved 2012-4-7.