This Catholic cathedral was completed in 1887 by Monseigneur Pigneau de Behaine.
It was closed in 1975 upon the reunification of Vietnam, and was not reopened until 1985.
The neo-gothic style of the cathedral looks somewhat out of place in the busy streets of Hanoi, although it's built in what's considered to be the French quarter of the city.
The church itself has a striking presence, with its two large square towers, and can be visited any day of the week, making a quiet escape from the noisy Hanoi streets.
If you happen to be in Hanoi for Christmas, this is the place to visit. The courtyard of the church becomes a huge gathering point and takes on a real carnival atmosphere.
By Sarah Turner
Last updated on 30th January, 2015.