Fairy fort or stone ringfort in Castleroyan

In pasture, prominently sited on an elevation, with a steep slope SE–SW, on an E–W ridge bordering the N side of the Trimoge river, which lies 100m to S. The location commands excellent views along the river valley, and S over an undulating expanse of grassland. A derelict 18th-/19th- century farmstead is located that lies 20m to NW–N, associated with small rectangular fields arranged in ‘stripes’. Slightly raised, oval area (28.3m N–S; 37m E–W) defined by a stone-faced scarp (H 1.2m at SE, 1.45m at WSW) topped with a low stony lip (Wth 3m), overlain NE–SSW by a later property wall. The cashel is incorporated into a later system of drystone field walls, which both encircle and radiate from the cashel, and it is difficult to determine to what extent the surviving stone facing and wall footings, which are in general ruinous, represent original enclosing features or relate to this later phase of modification. Stone facing in rough courses of large stones is visible at SE and W, but elsewhere the scarp is largely sod-covered or consists of a slumped jumble of stones. At N, the remains of a semi-circular feature, possibly a limekiln, is built into the external slope of the scarp. Remnants of an outer enclosing scarp or wall, with an intervening gap or fosse of varying width (Wth c. 3-4m) can be traced at NE–W, also greatly modified by, later field walls. Again it is unclear to what extent these are original features. The interior is level, but has an uneven surface. In the SE quadrant, there is an opening at ground surface into a Man-made underground passage passage (MA072-081001-). In the W half of the interior, there is a shallow, oval depression (5.8m E–W; 4.4m N–S; D 0.3m) defined by a stony rim, with a low linear stony rise (Wth 1m; H 0.15m) extending for 5m to E from it; it is possible that these features may also relate to the Man-made underground passage.