On an excursion to the mountain where the last Irish wolf was killed in 1786, Whelan collected 43 rocks from within the mountain itself. They are stacked in the form of the ancient structure of a cairn, which appears in many diverse cultures across the world. It has many functions including as landmarks and markers of burial sites. The rock structure itself is made up of crystals of graphite, sericite, chlorite and fine-grained mica which, depending on the viewers position, impart an uncanny silvery sheen from its surface.