[1] From the top end of the car park, take the track leading up towards the clump of trees, go through gate and then continue on an elevated route with your first objective, the Lansdowne Monument, on the skyline ahead and slightly left. Beyond a metal gate, the track becomes heavily rutted – although a bridleway, it is regularly used by ‘off-roaders’.
(A) This track formed part of the London to Bath coach road and Calne, a few miles to the west, established itself as a busy coaching town with several hotels and inns taking in travellers. When the railways came in the 1840s the importance of this route declined.
[2] You eventually pass a tumulus – an ancient burial mound – on the left and a short distance further you reach a junction. Turn left and walk uphill to farm buildings, where you fork right, climbing the stile and following a greener track to a further stile and entering National Trust land. Continue for a short distance until the track bears left; here, leave it and climb the undulating downland to the right, to reach the ditch and embankment of Oldbury Castle. Once on the embankment, go right and walk to its end, where you have superb views westward towards Calne and beyond, while down to your right is the Cherhill White Horse.
(B) Oldbury 'Castle' is an Iron-Age hillfort, enclosing an area of about 25 acres and defended by sections of single and double ramparts and a ditch.
(C) The Horse is 131 feet long and was cut into the chalk in 1780 under the directions of a Doctor Allsop, of Calne, who shouted directions through a megaphone. The horse originally had an eye filled with glass bottles to reflect the sun. These were stolen and recent replacements suffered a similar fate. The eye is now filled with concrete!
[3] Descend to the lower path and go left, heading for the monument; when you reach it you will appreciate its enormous size.
(D) The monument has a height of 125 feet and can be seen 30 miles away. It was erected in 1845 by the 3rd Marquis of Lansdowne to commemorate his ancestor Sir William Petty. The hill on which it stands is thought to be the highest point between London and Bristol.
Finding your way off the hillfort is no easy matter, even in clear weather. Stand with the monument inscription to your right (I’m assuming you have found the inscription!) and walk straight ahead on a level path with an embankment up to your left, noticing your next objective – twin radio masts – away to your right.
[4] When you reach a path doubling back down to the right, continue ahead to a wire fence. Keep the fence on your right for a short distance to reach a gate on the right that you go through. (A little further on, there is a stile in the cross-fence.) Now head downhill on an easy path, leaving the National Trust land via a gate and with a fence to your right. Continue for 700 yards to another gate and go through to a broad track. Follow this right, for a little over a mile.
(E) In the fields on the left, the Ordnance Survey map shows numerous burial mounds and enclosures, all of great antiquity. Few are easily seen from ground level, but those that are will be mentioned in this narrative. You are at this moment, walking along the course of a Roman road that is aligned with Silbury Hill to the east.
[5] Passing the field on the left, a pair of tumuli can be seen. Eventually, your track makes a short descent and you pass a Wiltshire Trust Nature Reserve sign on the left. Continue a few yards further to gates right and left. Go left into Morgan's Hill Nature Reserve and climb the hill, going through a gate at the top. Continue in the same direction, with the masts now over to your right, until a wire fence forces you right. Follow it for a short distance to join the Wansdyke.
(F) The Wansdyke is a linear defensive earthwork, consisting of a ditch and bank, thought to have been constructed between the 5th and 8th century A.D. It runs from the Savernake Forest near Marlborough to the Avon Valley south of Bristol, and is one of the largest linear earthworks in the country. The east-west alignment and the deep ditch to the north of the bank shows that it was from the north that attacks came; however, who was attacking who, is not known.
[6] Turn left and walk in the ditch, passing though a metal gate, then continue either in the ditch or on the left bank, depending on the weather! At the next gate, look left to see the rectangular outline of an ancient enclosure, visible in the field down to your left. The next stretch of path can be very overgrown, so make use of any clearer route to the side of the dyke. Continue to reach another gate, beyond which, you pass through a belt of trees and cross a track to a gate, before picking up the dyke again for a short distance to a gate and road. You are now at the mid-point of the walk (thought you’d like to know)!
[7] Be aware of the fast-moving traffic and cross the road with care, entering the driveway of a house then forking right and climbing a stile to regain the dyke. Continue to a pair of stiles with a track between. Here, you can choose to stay with the dyke on its undulating, narrow path, or you can take the easy option, going left along the track for a few yards, then turning right to follow the level, parallel route of a byway for the next mile. If you stay on the dyke, you pass through seven gates before reaching farm buildings where you descend left to reach the track. The alternative route has just one gate. From both paths, a Long Barrow is visible in the fields to the left and then the routes merge left of farm sheds.
Now, everyone must follow the track for a short distance to a junction where you go right, then through a gate on the left onto the dyke. (NOTE: You can stay on the dyke via a stile on the left side of the large barn, follow the dyke ahead, parallel with the track to a stile, cross the track to gate.) Continue over a cross-track with gates either side, then onwards to reach a gate farm track with a cattle grid on your right.
[8] Now, we leave the dyke for the last time and take the track left. From here on a clear day, you can trace most of your route, looking back along the dyke to the distant masts on the skyline, then tracking right, to the monument, and further right to the clump of beech trees through which you passed at the start of the walk. You have an easy, gradual descent along this track now, passing a wood on the right. Continue to the village and go left along the lane, bearing right with it to reach the main road.
[10] Turn left and walk beyond the bus shelter for a short distance, then cross with extreme care and descend to fields. Go diagonally across the field, aiming for that clump of trees, then at the top corner, cross a track and pass through a gate.
[10] Alternative route: It may not be possible to cross the field mentioned above. Continuing from [9] above, cross main road (A361) to bus shelter opposite, turn right and walk to roundabout. Cross A4 with extreme care and turn left uphill with the stables across to your left. Ignore first track on left but cross A4 at second track (byway) on left, go through gate on right.
Turn right and follow the path, bearing left to walk alongside the road up to the right. Eventually, you will come alongside the parked cars, look back down the path to see Silbury Hill in the distance. Now follow the fence to its end and double back to the car park.