If you are in District 5 of of Saigon, do make it a point to see the Thien Hau Temple there. Officially known as Chùa Bà Thiên Hậu (Pagoda of the Lady Heaven Empress aka Mazu), the temple is quintessentially Chinese in architecture. Whilst there are many Mazu temples elsewhere around the world that are bigger, or more grand, this temple is unique as it has that old school charm typical of Chinese diaspora temples.
Look at the roof ceramic diorama, the altar decorations and setup, and donation slips being hung in the temple, and you get transported back in time to when the temple was possibly the grandest ever built at that time in that area and was the focal point of the Chinese community in Saigon. Indeed this is one of the many temples that carries the timeless charm of old Saigon, Vietnam.