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.
According to VietKings (Kyluc.vn)