We will be arriving in London on the red eye at 8:30 am. We'll have 2-1/2 days on our own before joining a tour. The tour will include a "panoramic tour of Buckingham Palace, Big Ben, Parliament, Westminster Abbey, the Cabinet War Rooms, and a visit to the Imperial War Museum." The next day we go to Portsmouth. Then on to Normandy, etc. My question is, the day we arrive, what can we do so that we can make the day worthwhile even though we are going to be totally jet lagged? We're guessing that we won't be able to check into our hotel until late afternoon, although we should be able to check our luggage. We're staying at the Jolly Hotel St. Ermin's. Tour choice, not ours! Any ideas would be appreciated.