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