Oura Catholic Church, also known as the Basilica of the Twenty-Six Holy Martyrs of Japan, is a Roman Catholic basilica situated in Nagasaki, Japan. Completed in 1864, under the direction of a French priest Bernard Petitjean, the church stands as Japan's oldest church and was constructed in Gothic architectural style. It was designated as a National Treasure in 1933. Oura Church holds significant historical importance as it commemorates the 26 martyr Saints of Japan who were crucified in 1597 during the anti-Christian persecutions. The church became a pilgrimage site following the discovery of the 'hidden Christians' who had secretly maintained their faith through the centuries of prohibition. The church's stunning architecture, with its stained-glass windows, beautifully carved altar, and peaceful atmosphere, attracts numerous visitors, both as a site of worship and as a historical monument. The church is not only an emblem of the enduring spirit of Christianity in Japan but is also a testament to the country's complex history of foreign influences and cultural exchange.