The enclosure at Ballybricken, in County Limerick, belongs to that category. It does not appear on any historic Ordnance Survey Ireland maps, and as recently as 2005 to 2012 it could not be detected on aerial orthoimagery. Yet it is there, pressed into the undulating pasture, waiting for the right conditions and the right angle to give itself away.

The site came to light during the Bruff aerial photographic survey in 1986, recorded as Bruff 278, AP 4/3693, and logged by compiler Edmond O'Donovan. An enclosure, in the Irish archaeological sense, is typically a roughly circular or oval area defined by an earthen bank, a fosse, or some combination of both, used variously across the centuries as a farmstead boundary, a place of assembly, or a burial ground. What makes the Ballybricken example particularly interesting is the company it keeps: two further enclosures, catalogued as LI023-191 and LI023-192, lie approximately 250 metres to the south-west and south-east respectively, suggesting a pattern of settlement or activity across this stretch of land rather than an isolated feature. The enclosure sits roughly 180 metres north of the townland boundary with Gortboy and 320 metres east of the boundary with Ballyblake, positions that place it in a quietly marginal zone between named territories.

By 28 June 2018, the site had become visible again on Google Earth orthoimagery, which offers the most practical route to a first encounter for anyone researching it before a visit. On the ground, the pasture here is undulating, meaning slight rises and dips in the terrain that can obscure earthworks at eye level while making them legible from above as cropmarks or soil variations. There is no formal access or signage, and the site sits on private agricultural land, so any visit would require the landowner's permission. The associated enclosures to the south-west and south-east are worth considering alongside it, since the spatial relationship between all three features is part of what gives this otherwise modest site its archaeological interest.