Adakaya Shrine is most well known as being the starting point and destination of the Horanenya, the massive boat festival that takes place just once every 12 years. The boats used in the festival can be seen in the grounds of the shrine.
The main kami is Adakayanushitakigihime, indicating that Takigihime, one of Okuninushi's many daughters ruled over this area. The areas name, Adakaya, suggest a link with the ancient Korean kingdom of Kaya.
Within the grounds are secondary shrines to Kunisokotachi, another name for kunitokotachi, one of the primordial kami of the universe, Susano, Inari, and Omodaru, a kami I had not heard of before, but belongs to the generation of kami just prior to Izanagi and Izanami.
The most interesting aspect of the shrine is the two altars to Kojin which I have posted about before.