The example on the southern end of Gortaclare Mountain in County Clare takes the same basic idea and transplants it inland, using the natural drop into the Glen of Clab to do the work that crashing waves do elsewhere. The result is a structure that looks, at first glance, like an unremarkable rise of ground on a mountain plateau, yet resolves, on closer inspection, into a deliberate act of enclosure.

A promontory fort works by adding an artificial barrier, typically a bank, wall, or ditch, across the neck of a naturally defended spur of land, so that the occupants need only defend one side. Here, a mound wall runs across the promontory in a NW-SE direction for 37 metres, then turns NE for a further 8 metres before reaching the southeastern edge of the spur. That angled wall cuts off an area of roughly 1.8 hectares, a substantial pocket of ground by any measure. The fort does not sit in isolation either; it lies within a wider field system that spreads across the whole plateau, suggesting that whoever built and used this place was organising the landscape around them in some systematic way. A second mound wall, following the same logic, extends across an adjacent promontory immediately to the east, hinting that the arrangement was repeated rather than accidental. The site was observed by Ros Ó Maoldúin and is visible on aerial imagery from the 2012 to 2018 survey period, which is how many such low-profile earthworks come to notice at all, their outlines emerging from shadow and crop variation in ways that are invisible at ground level.