Not technically a Bike Park or Trail Centre, but certainly feels like one as cycling is allowed across much of the hillside, with a myriad of superb singletrack trails which provides the best off-road riding in the South East.
The (3.5km) Summer Lightning trail, now a loop, is the only waymarked trail in the area though, and it starts at the top of Leith Hill, by the tower. Signage isn't all that obvious at times, but it's a popular trail so follow the line of riders, or the tyre tracks.
There are three main hills: Leith, Holmbury and Pitch, each of which has a number of brilliant trails to explore.
Website: Surrey Hills Mountain Biking
WHERE: Surrey Hills, with a number of free (but busy) car parks.
Route type: Unofficial Bike Park