Ballygawley Mountains, a low mountain range which is an extension of the Ox Mountains include hills called Calliach a' Bhéara, Sliabh Deane, Sliabh Dargan and Aghamore Far. All these four have cairns at their summits. The hills are composed of a metamorphic rock called psammitic paragneiss. Near to Calliach a' Bhéara is a monument consisting of three stones, known locally as The Thief, the Boy and the Cow (Cloch a' Ghadai).