The Hidden Christian Sites in the Nagasaki Region are a remarkable ensemble of twelve locations in Japan that bear witness to the history of Christianity in the country. Inscribed as a UNESCO World Heritage Site in 2018, these sites include the remnants of Hara Castle, where the Shimabara Rebellion took place, and Oura Cathedral, which is significant for the 'discovery of the faithful'. They represent the resilience of Christian communities during a period of severe persecution and their secret continuation of faith under the ban by the Tokugawa shogunate in the 17th century.