The first word describes the function of the building. You may recognize the first part of the first word as the name of a Cambodian month. Interestingly, a clue to the meaning of the word here can be found by thinking about the (Western) horoscope sign which corresponds to that month, and the symbol associated with that horoscope sign...

This very same symbolic clue is represented visually in the photo as well, though it's a bit hard to see.