What to see

Given that you are a Christian, is there any place in Hanoi for you to come praying? St’s Joseph Cathedral is a very quick answer you may get.
Conveniently located at the end of NhaTho Street and the corner of Pho Nha Chung, the church is a popular destination for both Hanoiers and tourists from different regions in the world. While you find common places in Hanoi are easily accessible during the week, St's Joseph Cathedral is an exception. It is not usual to see the church doors open since the cathedral conducts mass on Sundays only; for the rest of time, the gate is kept closed. A small thing you should note down is to check mass schedule carefully so that your tour is better organized.
1. Notre Dame of Hanoi.
If you have ever known about the famous Notre Dame de Paris, you must go ‘wow’ right at the first time to have been here. St’s Joseph Cathedral bears a great number of resemblances to the original one in France. 
It was built in 1886 in Neo-Gothic Style. While the exterior is featured by walls of granite stone slabs, the interior surely impresses you by stained glass window and pointed arches. Specially, you may notice a statue of Virgin Mary in palanquin right to the left of the nave.
2. St’s Joseph Cathedral lemon tea
Passing St's Joseph Cathedral and stop for an iced lemon tea is a wonderful gift for your physical and mental status. For ones more familiar with routine life in Hanoi, this kind of drink attached to St’s Joseph Cathedral seems to be a perfect choice for humid and less windy evenings. Taking time sitting, relaxing and enjoying Hanoi in every single moment within one day, you can not help using the most beautiful words to express those amazing feelings.
In addition, the church is surrounded with a wide range of restaurants and shops displaying an influx of specialties from around the country. More excitingly, its proximity to HoanKiem Lake gives you the best chance to attend most of big events in the city. 
St’s Joseph Cathedral is not merely a place for praying and visiting, it is contributing a lot to build unique identities for the heart of Vietnam. All things considered, let’s spend time to come there at least once during your stay in Hanoi.