This is the museum _____ I visited with my friend last week应该填“which”还是“whom”?

This is the museum _____ I visited with my friend last week应该填“which”还是“whom”?
也就是说定语从句中在物类作先行词且在整个句子做宾语时关系代词用“which”还是“whom”?
感激不尽