This milestone marks the route of the old A31, an important route in the 18th and 19th century and part of the Turnpike formed in 1753 from Basingstone (near Bagshot) to Alton and Winchester. Subsequently, the current dual carriageway was constructed, by-passing Froyle and Bentley.
This Hampshire milestone dates back to c. 1825, with the top being inscribed with the parish name of Froyle, although now one would say that it is closer to Bentley. It shows that travelling eastwards it is 43 miles to London, 5 miles to Farnham, and 4 miles to Alton in the opposite direction.
The cache is placed very close to the milestone itself.
If you would like to set a milestone cache (a cache near a milestone) then please contact Marcusmaximi who is keeping track of the numbers. You may have to check on the "magic" map to make sure that a particular milestone is not a scheduled ancient monument or something similar.