nearest lanes to me are around cobham, theres a real gentle one maintained by the forestry commission by the old mausoleum, there's also another called jeskyns right close by, I've been on the mausoleum one loads of times, could almost drive it in a normal car. the jeskyns one seems okay, feeling brave drove it late at night, goes through the woods and a really tight pair of posts at the end, only just got my freelander through.
quite a few on the map, but haven't got round to investigating yet as I don't want to get stuck without carrying out a reccy first. finding time is a bit of an issue right now...