Can anyone suggest somewhere for a day out in London or the south east that is air conditioned and not likely to be packed to the gunnels this Saturday? Shopping centers seem an obvious choice, but I can't think of a fully air-conditioned one. Trains and buses around here are absolutely not air conditioned, so keen not to take one if it can be avoided. Literally anywhere to while away a cool couple of hours, get some steps in, maybe grab a bite to eat would be amazing. Suggestions welcome!