What's the point?
the A4, we continue South on the A361 (which regains its proper number here). On top of the hill to the West, there's a fairly substantial monument, raking the clouds.
From the A4, near Calne, it's a pretty sight - the hill has a big (natural) bite taken out of it, forming a vast amphitheatre. Cut into its grassy face is a small White Horse (probably not ancient, though it's never clear how such an image can be regarded as ancient, when it has to be re-cut periodically).
The hill top betrays the tell-tale lumps and bumps which are evidence of ancient fortification. Indeed, this hill is known as Oldbury Castle.
At the highest point of Oldbury is the monument - a simple stone needle. Even from here, 300 feet below, it looks big and impressive. Must be commemorating something or someone pretty important.
Unfortunately, there's no clue at the road-side or on a map. The only way to find out is to climb the hill.
300 lung-busting feet later, I discovered this inscription on the side:-
The Landsdowne MonumentDesigned by Sir Charles Barry and built in 1845 by the third Marquis of Landsdowne in memory of his ancestor Sir William Petty (1627-1684), Physician and Surveyor
Well, there's a pretty view from up here, and I probably needed the exercise anyway. I'll get back on the road when I lose this nasty purple colour from my face.