Cao Dai Temple is one of the most beautiful buildings I've ever seen, inside and out.
Cao means "high" and Đài means "dais" (as in a platform or altar raised above the surrounding level to give prominence to the person on it). Figuratively, it means that highest spiritual place where God reigns.
Don't miss it when you are visiting south of Vietnam. There are a lot of temples, but this one is a real charm.