回複：Any suggestions for a vacation from US to London, Paris

One week per city is a great plan.

No need to join tour groups. No flexibility.

In London:

Stay in the city (next to the subway), buy a London Pass or just buy an Oyster card for transportation. Plan your own tours.

Special note: all museums are free.

In Paris:

Take the L'Open Tour (multi-day) as transportation in the city. It goes to all the major attractions. Take the train to go to the suburb. Avoid the subway (pickpockets).

Special note: great food in Cafes.

Don't know about Rome.