Roughly 25 metres long and no more than two metres high at its tallest point, it sits at the edge of a cobble storm beach, its thin covering of sod worn away in places to expose a sandy core beneath. Upright stones protrude through the surface, and large slabs have been heaped against its flanks. It has the look of something deliberately made, and the feel of something only partially understood.

The western end of the mound is the most substantial part, rising into a broad, subcircular dome with a small cairn of loosely piled stones crowning the summit. Around the base at the south and south-west, a rough arrangement of upright slabs set radially into the mound, spaced one to two metres apart and filled between with horizontal stones, hints at the outline of a former structure, possibly the walls of a house. A low, sod-covered wall running up the mound slope at the south-west appears to be a later addition, laid over whatever came before. The eastern portion of the mound is lower and more irregular, its spine rising and falling in two small peaks, also clad in patches of large stone. Exposed in the south-western slope is a shell midden, the compressed remains of countless meals, a type of deposit commonly associated with coastal settlements across prehistoric and early historic Ireland, where the accumulation of discarded shellfish and other food waste can preserve evidence of long occupation. Whether the mound itself began as a natural sand-hill that was later shaped and built upon, or whether it was constructed from the outset, is not clear. Archaeologists have been cautious in their assessment, noting only that it may incorporate an early habitation site.

Inishkea South is an uninhabited island, and reaching the mound requires crossing to it by boat. The monument sits close to the shoreline on the south-eastern side, bordering the storm beach, where erosion continues to work at the edges and expose the layers within.