Route needed for starting endurance training

MarcBC
MarcBC Posts: 333
edited January 2009 in MTB beginners
I am not sure where to post this, but can anyone recommend an area S / SW of London (not too far out) where I can get 20-30 miles of road training done. It is for MTB riding, but I realise my endurance and general fitness need more work on before I can comfortably do more off road.

I want somewhere flat so that I need to peddle the whole time, with some interval stuff once a week on a Sunday morning. Around the Hampton area used to be okay along the river (there used to be a 10 mile TT there) but perhaps somewhat icy at this time of the year. Same also for Wraysbury (used to be a 25 mile TT there).

Where do you guys go riding when not off road?

PS this is in addition to my excercise bike training during the week.