There used to be a torii gate from Kumano Hongu Grand Shrine at this site. The name Daimon comes from the"big gate"of Kumano Hongu Grand Shrine. Dai means"big"and mon means"gate". There are other Daimon gate in the Kumano region.Koyasan's Daimon is a huge gate with guardian dieties. Daimon-zaka is a long slope leading up to the Nachi Grand Shrine gates. This oji is not as old as other ojis built in the Heian era. There seemed to have been shrine buildings at one time,but by the middle of the Edo era(1603-1868),all the buildings were gone. The curerent building was rebuilt in 1989. Beyond the building a small pagoda and a greenish-color stone monument are seen. This monument was built bu Kishu Domain which has become the present day Wakayama prefectural government.