I used to work for Teletext (remember that!) in London and they used to always have ridiculously extravagant Christmas Parties. One year, which might have been 2002, they hired the whole of HMS Belfast and set up a bar and casino. Pretty much all of the ship was accessible. I have happy memories of wandering round in a drunken haze and going to all parts of the ship. Not surprisingly the company went bust a couple of years later, although I think they still sell package holidays.
Have always wanted to visit HMS Belfast and managed it yesterday. Thoroughly enjoyable, although the visual experience was rather ruined by a hideous cruise ship moored along her starboard side. Cripes! Some of the ladders were daunting enough when cold sober!