My parents once visited and we had lunch in the restaurant on the ground floor, which they were very happy about. I then took them on a tour of the council chambers and some of the public areas and they enjoyed that too.
My housemate once visited but she waited by reception with a bag of cans until I finished up. We then walked to a gig together and got very drunk on the way.
No-one has visited my office on floor four though. I suspect they never will.