What makes the example at Annamult unusual is not its shape but its entrances. Most ring-barrows have one, or none. This one had three, positioned at the north-east, south-east, and west, each formed by a deliberate gap left uncut in the fosse, allowing passage into the central area. Three original causewayed entrances of this kind in a single monument is, to put it plainly, odd.

The site was recorded in detail by Prendergast in May 1954, who described a central raised platform some 34 metres in internal diameter, set within a fosse and outer bank, the whole thing constructed on top of what appears to be a natural gravel mound. The bank was said to have been low, only around 0.6 to 0.9 metres in height. That low profile may partly explain what happened next: in October 1954, the bank was levelled. The monument now survives in a diminished form, its most legible feature gone within months of being formally described. The unusual triple entrance arrangement prompted Gibbons, writing in 1990, to suggest the site might instead be a henge, a class of prehistoric ceremonial enclosure that does sometimes feature multiple entrances. The argument has some appeal, but the combination of an external bank with an internal fosse, along with the overall scale, points more firmly towards a ring-barrow classification. The natural sand and gravel hill on which it sits adds another layer of ambiguity, since the boundary between what was deliberately constructed and what was simply borrowed from the landscape beneath is not entirely clear.