This is 4-mile ride through heathland and woods, taking about 1.5 hours. Trailer parking may be possible in the car park adjacent to the Jolly Farmer pub (car park is for Whitmoor Common as well as the pub, and does get very busy). Roads mentioned are single-track access roads to houses on the common, so traffic is minimal and likely to be doing less than 10 miles an hour. The railway line is quite close to the track (which varies between a cutting and an embankment) and is the main Waterloo to Portsmouth line, so does see some fast trains. However, you're only close to the line for a total of about 20 minutes (at walking pace).
From the open grassy area behind the Jolly Farmer pub with your back to the pub, you'll see a wooden Permissive Horse Ride sign on your left.
Take this track through the woods (it runs parallel to the railway line).
Cross over the small wooden bridge, keeping the railway line on your left.
Keep going across the open heathland, until you come to a large bridge (the "Monkey Bridge") over the railway line.
Cross this bridge, afterwards taking the right fork in the path through the woods, passing a small paddock on your right.
Continue straight until the path forks.
Take the left fork at the Permissive Horse Ride sign, then turn right and then left at the next Permissive Horse Ride sign. You'll be on a fairly sandy little track.
Turn left just before the gorse bushes along an open track (the railway line should be in front of you a little way off).
Turn left at the end of this track, so the railway line is parallel to the path and on your right.
Cross back over the Monkey Bridge.
Once over the bridge, take the path straight ahead which crosses an open grassy area and then onto a wide, long sandy track (good for a canter).
Keep going along this wide track, passing a wooden bench on your left.
At the end of the track is a large, sandy open space. Turn left at the Permissive Horse Ride sign toward the Salt Box Road car park.
Continue past the Salt Box Road car park (its on the right as you ride through).
Enter the woods, continuing until you come out of the trees and cross over a small grassy area.
Keep right onto the access road heading toward Monkey Bridge (there are a few houses on your right).
Turn left before the bridge and back along the track you originally rode up.
Before the sandy part of the track ends, look for a track to your left ("Mount Pleasant") and follow this track across the open heathland.
Keep going straight until you reach a hard tarmac track.
Turn right onto this track.
Follow the tarmac track over a little wooden bridge, staying on the hard track which veers to the left after the bridge.
Cross straight over the access road at the end of the track, passing to the right of the wooden access barrier.
Turn left, following the Permissive Horse Ride signs up Jordan Hill (lovely canter here on sandy ground).
At the top of Jordan Hill, turn right and go across the top, past the little wooden bench on your left and down the hill the other side through the trees until you come to another access road.
At the access road, turn right passing Gooserye House on your left.
When the access road divides, take the right fork, then on your left will be another Permissive Horse Ride.
Take this path, which crosses an access road (there will be a house on your left).
Follow this Permissive Horse Ride through the woods, until you reach a wooden barrier, passing to the right of the barrier and turn left onto the access road.
Immediately on your right there is a Permissive Horse Ride sign (its easy to miss, so keep a look out).
Take this track until you see a wooden bridge to the right.
Turn left, away from this bridge.
Continue straight ahead until the path meets the access road.
Turn right onto the access road.
You'll end up on the grassy area next to the Jolly Farmer pub.