During the Sengoku period, the Kuromon (Black Gate) was the back entrance into the Akizuki clan’s Mt. Kosho Castle.
When the Kuroda clan was appointed to govern the Akizuki Domain during the Edo period, the gate became the main gate.
The gate was later moved to Suiyo Shrine and became the shrine’s entrance. The beautiful autumn foliage in the area is a magnificent sight.