This museum showcases the various sites associated with the UNESCO World Heritage Site "Hidden Christian Sites in the Nagasaki/Amakusa Region," including the Hara Castle ruins, the Hinoe Castle ruins, and the educational institute Arima Seminary that had promoted the Christian faith. Visitors can learn more about the history of Christianity in Nagasaki, from its arrival and flourishing to its violent suppression, as well as the Christian undercurrents that persisted and were eventually revived.