St. Joseph's Cathedral is a church on Nha Tho (Church) Street in the Hoàn Kiếm District of Hanoi, Vietnam. Its a late 19th-century Gothic Revival (Neo-Gothic style) church that serves as the cathedral of the Roman Catholic Archdiocese of Hanoi to nearly 4 million Catholics in the country. Construction began in 1886, with the architectural style described as resembling Notre Dame de Paris. The church was one of the first structures built by the French colonial government in Indochina when it opened in December 1886. It is the oldest church in Hanoi. The cathedral conducts mass several times during the day. For Sunday evening mass at 6:00 PM, large crowds spill out into the streets. The prayer hymns are broadcast and Catholics who are unable to enter the cathedral congregate in the street and listen to hymns.