Portal tombs, sometimes called dolmens, are among the oldest human-built structures in Ireland, typically consisting of two or more upright stones supporting a large capstone, and dating to the Neolithic period, roughly four to six thousand years ago. What makes the Ballycasheen example quietly striking is not what remains visible but what has been reclaimed: scrub vegetation has grown so thickly around the monument that only the interior of the chamber can now be seen, the outer form of the structure largely swallowed by undergrowth.

The contrast between past and present is documented in two photographs taken sixty years apart. In May 1952, the monument stood largely clear of vegetation, its stones readable in the landscape. By June 2013, the scrub had closed in substantially. The structural details of the tomb were recorded by Ruaidhrí de Valera and Seán Ó Nualláin in their Survey of the Megalithic Tombs of Ireland, Volume I, covering County Clare, published by the Stationery Office in Dublin in 1961, where it appears as entry Cl. 63. That survey remains one of the foundational catalogues of megalithic architecture in Ireland, and de Valera and Ó Nualláin's fieldwork across the country in the mid-twentieth century documented many monuments before significant deterioration or encroachment had set in. The Ballycasheen tomb is a small illustration of how quickly a site can change between one generation of observers and the next.