Having read the following on the ‘UKeGuide‘ site …
Amongst the attractions found at Farnborough is Tower Hill, Cove where a large accumulation of Sarsen stones exist, of various sizes.
… I asked on Streetlife where these might be as I’d been on Tower Hill road a few times and managed to miss them. Apparently although Tower Hill was probably once littered with many stones the area is now almost entirely built up and any remaining stones are likely to be on the smaller size and incorporated into garden rockeries.
There aren’t many decent sized stones of any kind to be found in this area so I thought I’d take a few pictures of ones that I have come across near the Deepcut/Pirbright barracks on the Basingstoke Canal side.
I’d guess that the middle picture is of a Sarsen Stone mentioned in this old but humorous website of a band of cyclists that used to frequent the ‘Old Ford’ pub at North Camp. The ‘Over the Hill Off-Road Cycling Club’. Look under Friday Rides – The Sacred Rock.