In a time with a heightened focus on how museum architecture and exhibition design shapes the museum visit, the entrance space of museums, the museum lobby, is remarkably absent from the museum literature and research. Still, the museum lobby is the first encounter visitors have with the museum and the last impression that they take home and share with others. This article analyzes museum lobbies as communication spaces in order to identify the different functions afforded by such spaces. In an explorative study of five Danish museum lobbies, we offer a preliminary categorization of these functions that can be compared at a general level. Concrete examples will be used to discuss general issues such as the adaptive borders of lobby spaces and the counteracting effects of design. We suggest that the preliminary categorization provided here can form a foundation for further studies resulting in practical suggestions for design improvements.