Next month we fly into Heathrow early and stay overnight. Then the next day we fly out at 6PM. We thought of renting a car and touring around nearby. So we're looking for suggestions. We've been to Windsor Castle. Maybe a pretty ride with small villages to stop at. Thanks for any ideas.
where are you staying? with 2 full days you have beaucoup choices
Have you thought about Osterley House and surrounding park? It's about 6 miles from Heathrow . The house dates from the C16th but was transformed in the C18th into a stunning neo-classical building by Robert Adam. grand 16th-century mansion completely transformed into an elegant neo-classical villa by the renowned architect Robert Adam in the late 18th century. Do a google image search to see what the rooms are like - they are magnificent. There re formal gardens as well as a vast estate with parkland and lakes. You coukld easily spend a full day h
ere.
A bit further is Runnymede and Ankerwycke where King John Signed Magna carta and also the J F Kennedy memorial (the only piece of American soil in the UK) and the Air Force Memorial commemorating over 20,000 Commonwealth airmen and airwomen who died during the Second World War and have no known grave.
waslekys has given you two good choices but they are both close to Heathrow and it's probably not worth hiring a car for them. Clearly you could do an hour or two's driving with the time you have so there are a huge number of choices.