The Sisters of St Paul of Chartres is the most long-established woman's congregation. It was created in 1696 and now counts 4,000 Sisters throughout the world. 1000 of them are in Vietnam. In Da Nang, they are involved in many healthcare, educational, and even infrastructural programs.
The Sisters of St. Paul de Chartres arrived in Vietnam in 1860, opened orphanages and hospitals, and they have been involved in many projects helping the poor and the disabled ever since. The cathedral's architecture is remarkable, but it is not always open to the public. Still, it's worth taking a look at the church architecture from the outside. It is better to contact them on their official website to see how you can help, donate money, or get involved in one of the many projects, including running orphanages, schools, providing healthcare programs in villages and HIV prevention programs, empowering women, just to name a few.