You can cycle from Waterloo in south central London to Woolwich in south east London, entirely on quiet streets and protected cycle lanes.
The route is 16.4km long (10.2 miles) and makes use of the Cycleway 14, Cycleway 4, and the Thames Path, as well as various quiet streets and paths to connect them up.
If you find this video useful or you just enjoy watching it please remember to subscribe to the channel and hit the bell icon so you're alerted to new videos, as I try to post new ones like it every week.
And if you like what the channel is doing, you can also contribute to the London Cycle Routes Patreon below. It really helps keep the channel going:
http://patreon.com/londoncycleroutes
You can see a digital map of the route and download a GPS/GPX file to use on whatever device or app you want here:
https://www.komoot.com/tour/1629302641?share_token=adwoCWFHd1LN1snwq4Fee44UTndw4nXMJF8EEm6H4t8z3P0lhu&ref=wtd
And you can find a viewer-created and maintained map of all the London Cycle Routes videos here:
https://www.google.com/maps/d/u/0/viewer?mid=1h9Hxm57fPvZmcuSXajM_Wu0G0s6f_bs&ll=51.505213496092054%2C-0.1285238120117249&z=12
I also highly recommend the Safe Cycle London map for route planning, which is compiled by @SafeCycleLDN on twitter:
https://www.google.com/maps/d/viewer?mid=1XlpvN9R-Wg7qZHyezO8y-eVlftr4e0WX&hl=en&ll=51.516975804561284%2C-0.21828576419061996&z=11