Until the house shown on this map was demolished in about 1946 it was the seat of the Rollo family.
(Click here for more information about the house).
Ask almost any local and they'll tell you the stone marks the spot where Lord Rollo's favourite horse is buried, or where it collapsed and died. It makes sense. His estate with Duncrub House at it's centre was large enough that he'd certainly have ridden round it.
The stone itself is a little puzzling. It looks like it was made to stand vertically with the bottom part set in the ground, as a gravestone would be. It might have been originally installed this way then fallen over, or it might have been laid flat. Either way the surrounding trees have grown considerably since, and the roots of the closest tree have grown enough to move it to it's now very tilted position.
It seems unlikely that a horse would have been buried so close to a main driveway to the house. The estate included several farms and would have employed a good many horses so it's likely this one's body was disposed of in what was then the usual way, and the stone simply marks the spot where it died.
But questions remain: Surely if it was a gravestone or a commemoration stone for a favourite, it would have had the name of the horse on it? And perhaps a date? As it is, we don't even know which of the Lord Rollos was involved. (The current Lord Rollo is the 14th to hold that title).