england1780

Agree here- maybe I didn't word it correctly- but 6 days in London itself is enough to cover most of the major, obvious must-see attractions. But you won't be able to see everything. I know many people who have lived near London for 30+ years and have never seen Stonehenge (not too far from London if you're a local), Westminister, Buckingham Palace, etc.
The good news is that you will never get bored!

irishface

Just a thought here. I don't know if you are a city mouse at heart, but most of the suggestions and your wishes seem to be for cities. Good as there is so much to see in areas covered easily by public transportation.

However, I am a country mouse, and much as I love cities and their wealth of things to do and see, I find myself tiring after a week of the hustle bustle and relieved to spend time in the country.

You might want to spend a bit of time outside of the cities

1 week London

3-4 days in Kent, Sussex or East Anglia

1 week Paris

3-4days in Loire

1 week Florence, Rome, or Venice

3 days in Umbria or Tuscany

This allows for coming and going to US and travel time between venues.

And PLEASE do not think of this as your only trip across the water! I am older than you and still traveling and still planning trips before I take that final trip and greatest adventure of all.