This is the 4057th most frequent Russian word.
музее
"Музее" is the prepositional case form of "музей," meaning "museum" in English.
In this sentence, 'музее' is used in the prepositional case, indicating the location where the meeting occurred.
Мы познакомились в музее.
We met in the museum.
Here, 'музее' is again in the prepositional case, specifying the place where the new exhibition is located.
Вы видели новую выставку в музее?
Did you see the new exhibition in the museum?
This usage of 'музее' demonstrates the prepositional case, showing where the action of buying occurred.