Saint Joseph's Cathedral is an ancient church in Hanoi, considered the best example of French architecture in the city, and features an intricate main altar with stained-glass windows, and consists of two square-shaped towers. This Gothic church dates back to the late 19th century and serves as the Catholic Diocese of Hanoi for about 4 million Catholics in the country. Entering this majestic church is like stepping back in time to 1886, when little has changed since it first opened its doors.