The Kinzan Kōzan-ji (金山功山寺) is a temple of the Rinzai sect in Shimonoseki, Yamaguchi Prefecture, established by Kyoan Genjaku in 1327. Kōzan-ji's Butsuden, completed in 1320, is a National Treasure of Japan. This architecture in Zenshūyō (禅宗様) style (Zen style), combining Japanese and Chinese design features. It is the oldest building designed in the Zenshūyō style that exists in Japan.