Maen Twrog (St. Twroy's Stone), Maentwrog church, Gwynedd. Maentwrog is a village and Community in the Welsh county of Gwynedd, lying in the Vale of Ffestiniog and within the Snowdonia National Park. Maentwrog literally means "Twrog's stone". According to legend, the giant Twrog hurled a boulder from the top of a hill down into the settlement, destroying a pagan altar. This stone is said to be the one located in the church courtyard. It is said that if one rubs this boulder one is fated to return to the village in the future. However the name was already in existence at some time before this as it is said in Welsh mythology found in the Mabinogion that Pryderi was killed at the Glaslyn river and in Maentwrog is he buried. The boulder supposedly hurled by the giant is the one said to mark Pryderi's grave. 咄ortean / TopFoto