We've bought a bike rack and would like to go for a day out cycling in the countryside somewhere no more than an hours drive (70 miles ish) from west london (ealing) so either M4/M40/M3 are good.
It has to be a reasonably good surface and fairly flat as we're not great cyclists and must be completely car free.
It doesn't have to be very long ... 4/5 miles ... have a picnic and cycle back.
Any suggestions welcome.