While references to Shean More date back to the 15th century, the Fitzgerald castle enters the historical record with certainty in 1580, when it was burned by the Earl of Ormond. The castle’s ownership changed hands dramatically following the Desmond Rebellion; Maurice Fitzgerald forfeited it in 1584, after which it was granted to Sir Walter Raleigh. The famous explorer and courtier promptly leased it to Thomas Colthurst, though by 1598 a Mr Duff had taken up residence. The property continued changing hands, being let to Thomas Jackson in 1640.

The castle itself is a rectangular tower measuring 12.65 metres east to west and 9.7 metres north to south, though it now survives only to first-floor level. Its base-batter and quoins, many now robbed out, hint at its former defensive strength. The main entrance, a rectangular doorway with a chamfered lintel on the north wall’s eastern end, leads directly to the ground floor chamber, which measures 7.45 by 5.5 metres internally. This level features embrasures in three walls and a mural chamber with a single gun-loop at the southern end of the west wall. Above the ground floor, a loft supported by corbels in the north and south walls features an east-west wicker-centred vault and would have been accessed via trapdoor.

The first floor, reached by mural stairs built into the eastern embrasure, contained embrasures in three walls and a now-destroyed fireplace in the south wall. A particularly well-preserved feature is the bartizan or machicolated structure at the northwest angle, accessed through a low doorway in the west wall. This defensive element has chambers projecting over both the north and west walls, each fitted with three gun-loops. The castle appears to have been surrounded by a rectangular bawn enclosure measuring approximately 40 by 33 metres to the north, though this now exists only as low scarps in the landscape.