Two possible ring-ditches show up as cropmarks on satellite imagery, each roughly eight to ten metres in diameter, sitting approximately thirty-three metres apart from one another. They leave no mark on the landscape that the eye can catch at ground level; only the differential growth of grass or crops over buried features betrays them.

A ring-ditch is exactly what the name suggests: a roughly circular trench cut into the ground, though what it enclosed and why varies considerably. Many are the eroded remnants of Bronze Age burial mounds, where the outer ditch that once surrounded a cairn or earthen barrow is all that archaeology has preserved. Others may have served as enclosures for ritual or settlement purposes. Without excavation it is impossible to say which category the Mannin examples belong to, and the notes of caution embedded in the word "possible" are worth taking seriously. The two cropmarks were identified and brought to wider attention by Jean-Charles Caillère, whose observation from satellite imagery added these quiet features to the broader record of prehistoric activity in the region.