I couldn't find a lot of information about Katsurahama Shrine, but I was able to find this:
Built in the late Muromachi period/1480.
Enshrines the Three Munakata Goddesses, the gods of the seamen, and the Three Gods of Usa Hachiman, the gods of military commanders.
Katsurahama beach was a nice quiet beach on Kurahashi Island, surrounded by a little pine forest. Another good day for a swim as well.
by Awkward-Action2853