San'yō region in the context of "Bizen Province"

The Chūgoku region (Japanese: 中国地方, Hepburn: Chūgoku-chihō; [tɕɯꜜː.ɡo.kɯ, -ŋo.kɯ, tɕɯː.ɡo.kɯ̥ tɕiꜜ.hoː, -ŋo.kɯ̥-]), also known as the San'in-San'yō (山陰山陽地方, San'in-San'yō-chihō) region, is the westernmost region of Honshū, the largest island of Japan. It consists of the prefectures of Hiroshima, Okayama, Shimane, Tottori and Yamaguchi. As of the 2020 census, it has a population of 7,328,339.

Hagi Castle (萩城, Hagi-jō) is a Japanese castle located in the city of Hagi, Yamaguchi Prefecture, in the San'yō region of Japan. Built in 1604 at the beginning of the Edo period as the main castle of the Mōri clan, it served as the seat of the Chōshū Domain for over 250 years until 1863. It was demolished in 1874 shortly after the Meiji Restoration. Its ruins were designated a National Historic Site in 1924. Hagi Castle has been designed as a component of the Sites of Japan's Meiji Industrial Revolution: Iron and Steel, Shipbuilding and Coal Mining, which received UNESCO World Heritage Site status in 2015.

San'yōdō (山陽道; Japanese pronunciation: [saɰ̃.joꜜː.doː]) is a Japanese geographical term. It means both an ancient division of the country and the main road running through it. The San'yōdō corresponds for the most part with the modern conception of the San'yō region. This name derives from the idea that the southern side of the central mountain chain running through Honshū was the "sunny" side, while the northern side was the "shady" (山陰 San'in) side.

The region was established as one of the Gokishichidō (Five provinces and seven roads) during the Asuka period (538-710), and consisted of the following eight ancient provinces: Harima, Mimasaka, Bizen, Bitchū, Bingo, Aki, Suō and Nagato. However, this system gradually disappeared by the Muromachi period (1333-1467).