I am traveling with my 2 teen aged daughters from the US to London, arriving Christmas morning, taking the EuroStar to Paris on 12/29, leaving on Jan 2 to travel back to the US - a quick trip I know. This will be my daughters first trip to Europe -- I have been to both cities but not in the past 20 years. Any advice on areas of each city to stay in, finding restaurants open or anything to do on Christmas day or NY day, anything outside the typical sites to see -- broad questions, I know ... Thanks for any suggestions.

It is quite late to be looking for Christmas/New Years accommodations - what is your budget?

There is NO public transport in London on Christmas Day so you will want to pre-book a car service like justairport.com to get in from LHR. And once in London -- no buses or Tube so after you decide where you are staying, book a nearby restaurant that you can walk to. Bear in mind that most restaurants are not serving but there are some in most parts of the city.

>>anything outside the typical sites to see<<

You are only in London 3.5 days and everything is closed on Dec 25 and most sites are also closed on Dec 26 . . . so you really only have the 27th and 28th for sightseeing, not a lot of time to see very much typical or not.

As Janisj says, almost everything is closed in London on Christmas day. But it's a great day for cycling, as there are no busses and little traffic. Or if you don't want to cycle; walking.
Hotel restaurants will be open.

Shops are open on the 26th; it's the first day of the sales and a very busy day in the stores.

Oh -- yes -- shops will definitely be open And massively crowded.

But not the major sites . . . British Museum, the Tower, V&A, Westminster Abbey etc etc etc are all closed on the 26th.

Here's a few things a quick internet search turned up.

Theater (many are open through the holiday)

Shakespeares Globe Theater the museum part

Sherlock Holmes museum

London Walks walking tours (www.walks.com)

Churches (like Westminster Abbey and St. Pauls)

Remember that you can also go to a church service even if there are not touring hours. It's amazing to hear their acoustics with a large choir or an organ concert.