Sin-Kamen (Синь-Камень, in Russian literally – Blue Stone, or Blue Rock) is a type of pagan sacred stones, widespread in Russia, in areas historically inhabited by both Eastern Slavic (Russian), and Uralic tribes (Merya, Muroma). Unlike Sledovik (both Sledovik proper and Cup-stones), Blue Stones did not have major hallows on them, and were venerated in a simpler way: by pouring water on them, or leaving food offerings. Some of the Blue Stones are still known, and to some extent venerated by local population.