Day trip from London to Paris.

Sharon, maybe just doing it on your own would work. There is a hop-on/hop-off bus that stops just outside of the Gare du Nord, where the Eurostar terminates. You could spend a good few hours touring, getting off and on as you pleased, have a nice late lunch somewhere and get back to London in time for a late dinner.

Very good idea! I've been to that station. I was reading about day tours and they sound a little rushed, and eating lunch on Eiffel Tower out of Pyrex sounds strange.

We have always booked Gray Line tours in both London and Paris. You can look up the tours, at Gray Line.com. Gray Line also works with One of the tours we took, was a full day tour of Paris. It was great. Plus we had a small group. We were in a van with just a few other people. Dependent on the tour, you are picked up at your hotel. Other times, you meet at a central point in Paris. It is over by The Hotel Regina. The Hotel Regina was featured in one of the " Jason Bourne" movies with Matt Damon. We also took Gray Line day tours to Giverney (Monet's Garden, highly recommend), Versailles, Normandy beaches, Mont St. Michel, etc.

Thanks, I'll check them out!

Don't overlook the option of taxis, which are not terribly expensive in Paris. On a recent trip with my parents, buses and subways ended up requiring more standing, waiting, and stair-climbing than were comfortable for Dad. Rick Steves' Paris guidebook suggests a one-hour loop tour that you can do by taxi to see the well-lit landmarks by night for a cost of about 45 euros (on the meter).