Natural England's Pastscape service desribes Troutsdale Pinnacle as "a cone of mortared rubble on the promontory of Troutsdale Moor".
It is a curiosity whose purpose (if any) remains a mystery, and whose appearance has, unfortunately, been marred by its latest over-enthusiastic coat of mortar.
It does not appear on the 1854 1:10560 Ordnance Survey map, but does on the 1894 edition.
There is a blank plaque (visible in our photograph) which shows no evidence of ever have borne an inscription.
Natural England suggests that the pinnacle might have been constructed as a local landmark to aid navigation, or as a memorial.
The most popular local suggestions are that a retired sailor built it to enable him to see the sea, or that it is a memorial to a child or landowner.
(The parish councillor who represents the area did not know of its existence before the clerk consulted him on my behalf.)
The pinnacle (SE923 896) lies on the very edge of a band of open access land along the top of the hill, and visitors should note that the inviting track climbing east from Troutsdale is not a right of way.