“On the farm of Knowley, stands an upright pillar known as the Tow Stone. Its significance is doubtful. Dr Stuart thought that it might of been the seat of tax-gathering in far back days (Sculptured Stones Of Scotland, vol. ii p. 44). But Professor Watson suggests to me that the name may be connected with the Gaelic toll, signifying a hollow.”
Folklore Of The Aberdeenshire Stone Circles 1926