Our museum is made up of an atrium and three exhibition halls in a lovely hexagon design as shown in the following figure:

The museum map

The main entrance of our museum takes the visitor into the atrium. Once there, they can visit any of our three exhibitions, but always have to come back through the atrium. We'll assume that if the user isn't within 5 meters of any beacon, then they're probably in the atrium and we'll let them know what else they can visit in our museum.