This one does none of that. On a gently south-west-facing slope at Castletimon in County Wicklow, a circular enclosure roughly thirty metres across lies completely invisible to anyone standing in the field. No ridge, no dip, no trace. The only way it has ever been seen is from the air, where differential crop growth betrays the buried outline as a cropmark, the kind of faint circular signature that appears in aerial photographs when soil disturbed by ancient ditches or banks retains moisture differently from the surrounding ground, causing the crops above to ripen at a slightly different rate.

The enclosure was identified through aerial photography catalogued in the Cambridge University Collection of Aerial Photography. Circular enclosures of this kind are a recurring feature of the Irish landscape and may represent the remains of a ringfort, a rath, or some earlier enclosed settlement or ceremonial space, though without excavation it is impossible to say which. They tend to date broadly to the early medieval period, though some are prehistoric. What can be said about this particular example is simply its shape, its approximate size, and its orientation on the slope. Everything else remains underground and unexamined.