This enigmatic structure has puzzled historians for centuries, earning it the local nickname “the sham castle” due to persistent rumours that it was never actually completed. When antiquarian John O’Donovan visited in 1839, locals told him the castle was “well begun but never raised any higher than it is at present”, whilst the scholar Thomas Westropp noted in 1900 that no written history could be found about the mysterious ruins, despite their prominent position within an extensive prehistoric field system.

The tower house itself is a modest affair, measuring roughly 6.2 metres east to west and 5 metres north to south, with walls surviving to about 3.5 metres high. Built from large mortared limestone blocks with steeply battered walls at the base, it shows little evidence of the dressed stone typically found in more prestigious buildings. The only hints of an internal stairwell are a single corbel and a perpendicular slab at ground level near the eastern wall, located in the northeast corner. The tower sits within a bawn of similar construction, with possible foundations of another building lying about 3 metres to the west and a limekiln built into the south facing slope beneath.

The castle’s various names add to its mystique; it appears as “Cashlaunawogga” on early Ordnance Survey maps, though O’Donovan recorded it as “Caislen-an-Mhaga”, and Westropp claimed the name “Caheremon” was supposedly transferred to it from a nearby cashel. Some writers have even suggested an ecclesiastical origin for the ruins, though this theory remains unproven. Whatever its true purpose and history, this atmospheric ruin continues to intrigue visitors, standing as a testament to an ambition that may never have been fully realised.