Koyasan is a sacred Shingon Buddhist temple complex located in an alpine basin founded by the high priest Kukai, posthumously known as Kobo Daishi (774-835). Kukai is one of the most famous people in the history of Japan. He was not only the founder of the Shingon school of Buddhism but a poet, engineer, and calligrapher. He was also the creator of the Kana syllabary of the Japanese language.
Koyasan is centered on Kongobu-ji Temple built in 816 and is divided into several areas. The entrance to this sacred site is marked by an impressive 25.8 meter high wooden gate.
Danjogaran is the religious center of Koyasan. The unique style of the temple complex is based on the Shingon doctrine exerted tremendous influence as the architectural model for nearly 4000 Shingon temples throughout Japan.
Kongosammai-in is 1 km east-southeast of Danjogaran and is the site of the oldest existing esoteric pagoda, the first of its kind in Japan. The total height is 14.9 meters and based on the model of an Indian Stupa. It is valuable as one of the representative examples of the esoteric pagodas built in the Medieval Period of Japan.
Okuno-in is 3 km to the east of Danjogaran and contains the place revered as the sacred area where Kukai entered into a supreme plane of meditation waiting for the arrival of the Buddha of the future. Over 300, 000 tombstones are densely distributed beneath giant 500 year old trees creating a spiritual atmosphere and profound religious cultural landscape.