Paris Pass

Mary suggest you don't want the "Paris Pass" but perhaps you would benefit from the "Museum Pass".
Since you are not sure how much time grandson will be spending with you actually sightseeing it does get a bit tricky, why buy him a 6 day pass if hes basically going to visit 5 or 6 sights with you max and on vary assorted days.. A good museum pass would benefit you if you enjoy doing a fair amount of sightseeing. A museum pass to "skip the line" only serves well at a few places Mary, lines are not horrendous at many places. The places a pass helps are the Orsay, Orangerie, Versailles and sometimes St Chapelle . The pass does not include the Eiffel Tower, so suggest that is one place you either arrive before it opens and get in line, or take the stairs( line is always shorter and stairs are not as horrible as you would think, lol ) , or prepurchase a tour that includes it ( would not be my choice except maybe the "Behind the Scenes Tour" offered on the official Eiffel Tower website , , which may be sold out at this date. Pass does cover admission cost to climb the Towers of Notre Dame, but does not allow line skipping there, and this is the place with slowest moving lines,, get there at least 35-45 mintues before it opens.. remember entrance to Towers is on side of building. Line that forms up front is for church and while it looks long it does move fairly quickly , visit it after towers. Be sure to take grandson to Invalids Army Museum, both my boys loved it, even my 11yr old dd and I enjoyed it.. its an undersung treasure in Paris I think.

Thank you for your suggestions. I think they are very helpful.

To add to Pat's excellent reply, the Museum Pass allows you to skip the ticket buyer's line at Ste-Chapelle, but not the security line; this latter line is usually the hold up. So, go to Ste-Chapelle as early as possible.

Evem better, go to an evening concert at Ste. Chapelle. Get there early and you'll have time to walk around and look at (and photograph) the stained glass before the concert starts. There are often 2 concerts, choose the one that begins before sunset.

You don't mention where your friends live. IME, the pass(es) that are right for your trip will be a function of the days that you are there, where you are staying, and what you plan to do. If you are staying outside of Paris center (ie beyond zone 3), and will be riding trains and/or RER to and from Paris each day, then a transportation pass will be essential. Whether you get the Navigo Decouverte or a Paris Visite will depend on what days of the week you are there. Both of those will cover your transportation to/from the airport as well. But if you are not doing consecutive days of touring, you may just want to get individual Mobilis passes for each day. On weekends, you could buy your grandson a Mobilis Jeune, which is offered at a significant discount. If you want to visit a bunch of museums in consecutive days, a museum pass is nice to have. Others have explained that well.

The pass also works at Versailles. DO NOT GO ON THE WEEKEND OR TUEDSAY!!! Get there early, we had to wait in line for an hour even with a museum pass.