Usa Jingu: The Usa shrine is one of the most famous in Japan, and has long been the recipient of Imperial patronage. In actual fact, in all of Japan, it is considered second only to Ise Jingu. Interestingly enough, for believers, it is the home of Emperior Ojin, who was deified as Hachiman-jin (The God of Military Power).
A little history: The shrine was founded in Kyushu during the Nara period. Ancient records place the foundation of Usa jingū in the Wado era (708-714). It is today the center from which over 40,000 branch shrines have grown. Usa's Hachiman shrine first appears in the chronicles of Imperial history during the reign of Empress Shotoku. The empress allegedly had an affair with a Buddhist monk named Dokyo. An oracle was said to have proclaimed that the monk should be made emperor; and the Kami (God) Hachiman at Usa Shrine was consulted for verification. However, the empress died before anything further could develop...
Best wishes from Oita, Japan.