The ditches on Grindstone Law 'are' the entrenchments made and used during a battle on Duns Moor - an area on its southwest side. Naturally one of the combatants was called General Dun, "who gained a victory there against great odds".
On the north east side of Grindstone Law (as far as I can make out), "there formerly existed an upshot spring of considerable volume, called Hell's-cothern (caldron). It was supposed to be unfathomable, and the boiling-like motion of its water was attributed to its connections with subterraneous fire.
"In association with this spot, the following story is extant: --Once upon a time, a team of oxen, yoked to a wain, were engaged on the top of the hill [the Law], when, from some unexplained cause, the beasts became unmanageable, and furiously dashed down the bank towards the Cothern. On passing over the brow of a declivity midway between the top and the bottom some accident brought the stang (pole) into violent collision with the ground, producing a deep laceration, from the bottom of which a well that yet remains first sprang up. Unarrested by this obstacle, onwards the oxen swept down the bank (the abrasion occasioned by their wild descent being still traceable in the course of the well strand) towards the infernal Cothern, in which oxen, wain, and driver sank for ever, the horns of the oxen alone excepted, which were shortly after cast out by the unusual surging of the fountain.
Such is the legend. About fifty years since the two landlords of the estates divided by the burn deepened its channel [..] the water which was wont to boil to its surface found a subterranean outlet to Denises-burn [..] Some there are who have seen the Cothern in its pristine state, and remember the awe which the story imparted to a sight of it.."
I do like this story, even if the language is ridiculously flowery. Bottomless springs, connections with the underworld, bulls..