Somewhere in Buckinghamshire would be a great bet.
There's a campsite just under Ivinghoe beacon, so only a 40 min run to Ace through the Chiltern Hills.
Been there once for an ABR meet. I live about 10 miles from there, it's far enough outside London to be nice, but still close enough to go to Ace.

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Bike: 2013 XT660Z, TKC70 tyres

Mods:
Barkbusters, Scottoiler, DIY Tail Mod, DNA Stage 3, Power Commander V & O2 Eliminator, Exan X-Black Stainless exhaust, Tool tube, Ohlins linear front fork springs, Nitron rear shock, JT front and Supersprox rear sprockets, D.I.D. VX 520 chain, Adventure Spec bashplate, DIY USB Outlet, DIY chain guide, Kev's Throttle mod

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