BRECON BEACONS, WALES—While walking in the Brecon Beacons, geologist Alan Bowring spotted prehistoric rock art on a 4-foot, 9-inch long stone lying on the ground. The stone, decorated with 12 cup marks joined by connecting lines, may have stood upright during the Bronze Age as a way marker for farming communities. “We might have been able to predict a discovery of this kind considering the large amount of prehistoric ritual sites in the Brecon Beacons but this is the first evidence of prehistoric rock art to be ever recorded [in the Beacons],” commented George Nash of Bristol University to BBC News.