Just west of Carran village, a large subrectangular enclosure stretches roughly 150 metres east to west and 140 metres north to south, its defining walls quietly absorbed into a landscape that has been reused, redrawn, and resettled across several millennia. Later field walls cut across it on a northeast-southwest axis, and two trackways or droveways extend from it, though whether these belong to the original design or were added at some later point remains uncertain.

The enclosure is one of five prehistoric enclosures identified on the Carran plateau. Its walling closely resembles that of a comparable enclosure roughly 1.4 kilometres to the southeast, and that neighbour has been dated to the Late Bronze Age, a period running broadly from around 1200 to 600 BC, when communities across Ireland were organising land, grazing animals, and marking territory with increasing formality. The Rannagh enclosure is understood to belong to the same phase and tradition. Within 300 metres to the north, southeast, and south lie three cairns and two ring-barrows; ring-barrows are circular burial monuments defined by a low bank and internal ditch, and their clustering around this enclosure suggests the plateau was a place of sustained and varied significance, not simply a functional enclosure dropped into empty ground. The accumulated archaeology here represents generations of deliberate return to the same elevated limestone terrain.