After months of lurking on this forum, I am finalizing plans for our visit to London in 20 days! We have rented a flat in North Kensington. We arrive on a Sunday afternoon and will take a car service from Heathrow to the flat. If not too tired, we will do some exploring of the immediate area, and would like to buy 7 day Travelcards. Our nearest tube stop is Ladbroke Grove, which I understand is not a National Rail station. Is there a National Rail station within walking distance? If no, I would appreciate any suggestions as to which station and how best to get there. Thanks in advance for your help.