We're going for a day in a few weeks time - coach gets into Bercy (thankfully only a couple of hours from inside France) then we have a day to do Montmatre, Citadium/Galeries Lafayette, Marais etc.
For time we'll have to get some metros/buses - we are 2 DCS 14 and 16 and 18yo DS and DH and I. I think they all count as adults though.
Is it worth buying a navigo easy pass (once we've got them I presume we can reuse if we visit again) to load up with tickets or just getting a day mobilis pass? And do you still need to validate tickets in the funny machines that chomp a bit out? I got in royal trouble once with an inspector for not realising I had to do this.
Thanks