Wiki defines a museum as follows: "A museum is an institution that cares for (conserves) a collection of artifacts and other objects of artistic, cultural, historical, or scientific importance..."
If a "convent" is an "institution", and "mummies" are objects of cultural and historical importance, then the most impressive "museum" I have seen in my trips around the wolrd are the Catacombe dei Cappuccini below the Convento dei Frati Cappuccini. It contains the largest collection of mummies in the world, exposed on the walls of barely illuminated catacombs. I have to admit that this scary concept of exposing corpses can be questioned. However, when you stand in the middle of these mummies, and many of them are still dressed in their original clothes, some hundred years old, and with some phantasy, you think you travelled in time and arrived in the 17th or 18th century.
Happiness is when what you think what you say and what you do are in harmony.