Cutty Sark, Greenwich, by the foot tunnel entrance.
11am. 33 miles total distance. 10-minute comfort breaks at half-way points. 75 minute lunch stop at historic & picturesque Lion Inn, by the Darent river path. Back by16:30 Pace will be relatively easy, to steady and whatever you can manage up hills! Expecting 10mph/16Kmph average. Map: https://goo.gl/maps/WM6i6KmVL7Q2 (precise route subject to modification but distance/elevation won't vary much).