hello lovely people of DiS!

my friend jack is here and we're supposed to be having 'london fun day' today.
where can we go thats FREE and fun?
im thinking interesting museums/galleries etc?
he wants to go to the tate but i dont want to take him there as thats what everyone always does and i've been a million times and quite recently so MEH

please give ideas with locations, cheers!

ps. does everyone else find that coke (cola) helps the nausea that comes with a hangover? if you haven't tried it before, try it next time you feel like your stomachs going to unravel after a night of drinking. it really settles it.