The Rocking Stone of O Pereiro Curiosity · Alfoz do Castrodouro, Mariña Central, Lugo Image of Alfoz do Castrodouro, not of the place itself. A granite block in the parish of O Pereiro set in such a way that it can be moved with a push without ever falling; rocking stones were held to be places of justice or of ordeal in Galician tradition. Photo: Elisardojm (CC BY-SA 4.0) What to see and do in Alfoz do Castrodouro