Post-London Tour Travel

I assume you mean the RS London in seven days tour. A crucial question to ask is how much time could you spend after the tour? Are you determined to keep your hotel in London and make daytrips only, or are you willing to consider overnight trips? From London, Brussels would not be my first choice. Paris is only 2 hours 15 minutes from London by Eurostar. Paris. Let me say that again. Paris.
Other choices include: Bath, the Cotswolds by tour or rental car, York, Stratford upon Avon, and Edinburgh. Using discount airlines, you could easily do a few days in Berlin, Amsterdam, Nice/Riviera, Madrid, or Barcelona. Bruges is near Brussels and well worthwhile, and Cologne isn't too much farther than Brussels. Really there are a wealth of attractive spots easily reached from London, depending on your budget, time available, and likes/dislikes/interests. Other posters will no doubt provide even better suggestions.

Thank you for the response. My head is spinning (in a good way) thinking about your suggestions! Let me try to clarify my goals for the trip extension. I am taking the RS London 7 day tour. I only wanted to spend a few extra days (3-4) on this trip. If it were another year, I would have more time to travel further and longer in Europe. My original goal was to make the trip overnight. I wanted to pick a place that I could experience in a couple of days. This is why I thought of Brussels. Brugges is added to my list.
Paris is one of my favorite places, and it is a consideration, but I would like to see something new. In addition to the places near London that Roe suggests, what are other must see cities a train ride from London? I would like to fly in and out of Heathrow.

Joanna, Given the short time frame and the fact that you've already been to Paris, two cities that you might consider are Bath or York. Both are easily reachable from London in a few hours, and both cities are awesome! If you choose Bath, you could take daytrips to Stonehenge, Lacock or the Cotswolds. Have a look at This Website for some possibilities. Of the two cities, Bath would probably be the best choice. As I recall, it's possible to take the National Express Bus from Bath directly to Heathrow (check their website for details). I have to agree with Roe - Brussels would also not be my first choice for a side trip. Happy travels!

This might be of interest http://www.aaacarolinas.com/Magazine/2008/Jan-Feb/britain.htm?zip=28105&stateprov=nc&city=matthews Depending on your personal interests, Cardiff might be a good choice. there is a nice castle in the center of the city, the new soccer stadium gives tours, there is the harbor area to explore, slate mines nearby, and some great shopping- both markets and "high street" shops.

I would stay in England and either do York by train with a day or two exploring the York moors or the Cotswolds (but you needa car to get the best out of Cotswolds). York is a great City with wonderful cathedral, wall and some nice little streets to pke around in. Cotswolds are if you want to unwind in pleasant countrside with very cute villages and hamlets.