That pairing alone is notable, but the western tomb at Faunarooska carries an additional layer of strangeness: marked on a 1977 map just south-east of the site are what tradition identifies as the hoofmarks of the Glas Ghaibhneach, the supernatural cow of the legendary smith Lon Mac Liofa. Prehistoric monument and mythological trace sitting side by side, each apparently unremarkable in the rough grass until you know what to look for.

Wedge tombs are a type of megalithic burial monument characteristic of the Irish Bronze Age, typically consisting of a roofed stone gallery that narrows and lowers toward one end, often set within a cairn or mound. The Faunarooska example, orientated toward the south-south-west, has a double-walled chamber enclosed within a mound measuring roughly 8 metres east to west and 6.5 metres north to south. The chamber itself is estimated at a minimum of 3.5 metres in length, though much of it is now concealed beneath collapsed slabs that were most likely displaced capstones. The internal structure is still legible in outline: four stones define the northern wall of the chamber, the largest sitting at the western end; three smaller slabs form the southern side; and a pair of upright slabs closes the western end. Five large displaced slabs scattered through the interior, ranging up to 2.4 metres in length, are thought to be the remains of one or more original roofing stones. The outer walling survives unevenly, with the northern outer wall the most intact at just over 4 metres, while only two stones remain along the southern outer wall. Ruaidhrí de Valera and Seán Ó Nualláin recorded the tomb in their 1961 Survey of the Megalithic Tombs of Ireland, and a 1998 inspection found it unchanged from that earlier account.