Not an official audax, can't really expect to submit a DIY for this evening...
The Dorset Dynamo.
Start - Canary Wharf. Roughly sunset.
Get out of that London.
Start of the A30 at Heathrow airport.
If traffic's too hairy I'll go through Staines, but it should be late enough, and cycling across the Runnymede Bridge would be quite amusing.
Join the A303 at Popham, before leaving almost immediately at Michaeldever Station. Old A30.
Sutton Scotney - almost completing the A30 between Honiton and London.
Turn, head up to Bullington Cross. A30 complete. Rejoin the A303.
A303 to Stonehenge. Should be around sunrise!

Leave A303 at Willoughby Hedge.
Just over 200 km.
As for why the A303? Services. Imma need to eat. If I don't like the taster at Popham, I can follow the A30 all the way from Sutton Scotney, which I've done before. But then I miss out on Stonehenge 😢
Full fat option: Dunraven Doomsday, carry on to Dunraven bay for a 400 km.
Don't think I'll be up to it this time
