The Iwashimizu Hachimangu Shrine was designated as a national treasure in 2016 for its 10 shrine buildings including the main shrine constructed in the traditional hachiman-zukuri architectural style, and three plaques that record historical data such as the date of repair or the carpenter in charge.
The shrine is known for heavily exhibiting the influence of the syncretic fusion of foreign-imported Buddhism and the ancient indigenous religion of Shintoism.

The shrine sits atop Mt. Otokoyama, gateway to the southwest quarter of the ancient capital of Kyoto.
It was originally built there because Gyokyo, a Buddhist monk who lived during the Heian period (794–1185), received a divine message at Usa Hachimangu Shrine on the island of Kyushu in 859, telling him to enshrine Hachiman, the tutelary god of warriors, on the mountain to protect the country. As one of three major shrines in Japan built to enshrine Hachiman, the Iwashimizu Hachimangu Shrine is considered the second imperial ancestral mausoleum after the Ise Grand Shrine.

After the main buildings were restored by Oda Nobunaga, the corridors rebuilt by Toyotomi Hideyoshi, and the main buildings rebuilt by Toyotomi Hideyori, the current shrine buildings were built by Tokugawa Iemitsu.
The main shrine in particular is a grand complex built in the hachiman-zukuri style, surrounded by an inner and outer sanctuary that span 11 columns (nearly 40 m). The main shrine is the oldest and largest structure of its kind in Japan.

Though it has stood for so long, the Iwashimizu Hachimangu Shrine still imparts the importance of peace and friendship while conveying the distinct religious culture of Japan, where it is believed that both gods and Buddha accept all things and cherish all forms of life.