In Irish dolmens balls have been fairly common finds, often found in the structure's floor or lower level detritus, and often associated with bones - materials identified as forming the balls include marble (thought to be a slingshot); ironstone ; calcium carbonate; porphyry; and syenite - with sizes recorded were from approximately . Some of the balls found inside dolmen cairns in the region of Slieve na Calliagh in the County of Meath were claimed by E.A. Conwell to be 'brain balls' as described in historical sources and legend.