A wedge tomb is a Neolithic to early Bronze Age monument, named for its characteristic tapering form, wider and taller at the western end and narrowing progressively toward the east. What makes the Fanygalvan example quietly remarkable is not just its size or its state of survival, but what surrounds it: two further megalithic structures were added to the western end of the same mound at a later date, suggesting that people returned to this spot across generations and kept building.

When Ruaidhrí de Valera and Seán Ó Nualláin surveyed it for their 1961 volume on the megalithic tombs of County Clare, they found a monument around 4.75 metres long, divided into two chambers by a segmental slab, with the larger western chamber reaching 1.4 metres in height and the smaller eastern one dropping to roughly 0.65 metres. Several of the limestone slabs are dressed along their edges and tops, a detail easy to overlook but significant given the effort involved. The massive southern sidestone, over four metres long, does double duty as part of the wall of the eastern chamber as well. One large section of the original roofstone remains in place; a broken fragment of it lies on the ground just to the west. Traces of outer walling persist on both sides, more substantial on the south where five upright slabs and two recumbent ones survive in position. De Valera and Ó Nualláin noted evidence of doubled outer walling on the north side, and they argued that the narrowing of the enclosing mound between the wedge tomb and its two western additions pointed to the mound having been enlarged after the tomb was first constructed. The 1920 Ordnance Survey six-inch map marked the site as 'Cromlechs', an older general term once applied loosely to megalithic structures of various kinds.

The tomb sits within a wider prehistoric landscape. A stone row lies around twenty metres to the north-west, a standing stone roughly nineteen metres to the north-north-east, and the whole complex falls within a large multiperiod field system. The plateau looks out over hazel-covered cragland to the south and west, the kind of terrain that has changed relatively little in surface character since the Bronze Age, which gives some sense of the environment in which these monuments were originally placed.