So my DF and DM have just gotten to London as they have some work nearby.
They're originally from another EU country and although they've lived here for quite a few years never had a chance to see London until now.
The problem is they are clueless and didn't organise anything, DF knows what he wants to do/where he wants to go but doesn't know how, DM just waits for him to sort it.
I've just had a phone call from a slightly concerned DF (probably behind my DMs back as he wont admit he doesn't know
) asking if I can find out how they can get from their hotel via public transport to Westminster to see Big Ben.
I've tried looking at fares online but it's asking about underground zones etc and TBH I don't know what I'm looking at 
So I need to figure out how to get from Luton airport (near their hotel) to Westminster and more or less how much it would cost.
Please help?