The path starts on the former towpath round Windsor Park, then "for security reasons" crosses the river to the Datchet side. This substitute path wanders away from the river, and we found ourselves at times treading a careful line between shoulder-high nettles either side. After some stretches on the road as well, we eventually crossed the river again to a more established way. Despite increasingly close and frequent aircraft overhead, it could be tranquil here.
Soon we approached Runnymede, where the Magna Carta eighth centenary has been celebrated this year. This was busy with tourists and picnicers, and we had to queue for our planned break at the Magna Carta tearoom. We also saw a pop-up exhibition by Brunel University on the Magna Carta.
The path got busier as we approached Staines - now passing under the M25 and past the London Stone: signs that we were entering London.
The London walks must wait for the next instalment.