A friend of mine suggested that I check this website of a place in UK called Center Parcs to spend part of the summer vacation in it. The pictures below are from the one in Sherwood, mid of England and it’s around 3 hours drive from central London, but they do have other places closer to it (they have 3 more ones). I hate staying at London during summer, and never thought of going there no matter how fun it is for reasons probably many people know, yet I find this place an ideal one to visit in summer. Basically you book your accommodation there as they have different type of villas ranging from 1 to 4 bedrooms, and the activities there are just amazing for both the adults as well as the kids. This place is car-free zone, so all cars are suppose to be parked outside the resort. I’ve checked the price of the executive 2 bedrooms villa for 4 midweek nights, and it was around 800 pounds and that is really not bad at all.
They do have similar places in different locations in Europe. this is their website [link].