Ground rules: Date is Tuesday 21st Feb.Free or low cost. It's expensive just to get to London.I have a zone 1 & 2 tube card.Train times are non-negotiable (fixed tickets).I am going on the Maths in the City tour.All else is up for grabs. Make suggestions for places to go and things to see by putting pointers on the map. Explain why and give timings and a link if appropriate.For timed events: Remember to allow enough time for travel (for someone who doesn't know where they are going). Please don't delete other people's entries. If you disagree, by all means leave a comment to say so but don't delete something you haven't put there.