Yugasan Rendai-ji is a combined temple and shrine complex south of Okayama, with a more layered feel than a single worship hall. Its Bizen pottery torii gate is the detail to look for, and the site is also part of the Chugoku pilgrimage route.
It is not as central as Korakuen or Okayama Castle, but it rewards travellers who like regional temples with quirks. The connection to Kotohira's Konpirasan gives it another thread in western Japan's pilgrimage network.