You were so lucky to get those $205 flights. I tried from Tampa and think they must have had about one seat per flight. lol I could not find anything no matter how many dates I input.

You might think about a side trip to the Lake District on yor way up to Edinburgh. What a wonderful error...bet you just cried your little eyes out! :D

3 weeks instead of 2--wish my husband would make that kind of mistake!

I'd love to make a mistake like this!

I'd vote for taking the overnight train to somewhere in Scotland (we took it to Inverness last summer), then renting a car and driving back to London. Saves the cost of lodging for one night and gets you out in the country. Plus, it's an experience we don't get over here in the states very often.
We spent a little less than a week and drove back with stays in Edinburgh and York before reaching London. With more time to work with, you could really explore the countryside at your leisure!

i would consider renting a car at heathrow or at gatwick and spending a week wandering in the cotswolds and maybe even up into wales or in sw england and along the southern coast...driving is easy outside major towns so it will not be a problem...in london is another story if you have never done it---that's why i suggested renting at the airport or any place outside london....take a train to oxford and rent there for instance...

Definitely plan your trip before deciding whether to rent a car or utilize a rail pass. Cities like York, Bath and Edinburgh can be toured without a car(parking hassles) while places like the Cotswolds, Scotland, Wales and the lake district are best toured by car. Consider using a Britrail-Drive pass which gives you a day of train travel here and a day of car rental there. Rick Steves' Great Britain book has an interesting 3 week tour of GB by car which would give you some idea of where to start and how to travel around.

You are coming to England at a perfect time - hope you get some lovely spring weather. Can I suggest going to Edinburgh but stopping off in Yorkshire for a few days. York is lovely and the Yorkshire Dales will be beautiful. Harrogate is an interesting Spa town with good shopping. Durham is also nice for a day or so. A GNER train from London to Edinburgh stops at both York and Durham so you could get away without a car is you just wanted to do cities. if you want to head into the Dales then a car is vital - but you could rent one from York or Durham if you wished. Someone earlier appeared to a bit scathing about Leeds - well, in nits defence it actually has some of the best shopping outside London AND has the advantage of great shops in a very compact area, plus some good restaurants. I wouldn't stay in the City though.
Some suggestions of castles and places to stay -
1) We had a great weekend at Lumley Castle, close to Durham.
2) Seaham Hall Hotel, same area has a good reputation but might blow the budget!
M