Cerrig Cyfamod Glyndwr

[Here are] two unhewn blocks of white quartz, almost certainly placed by artifice, with a small natural outcropping boulder midway between them, to which the local tradition points as marking the site where Owen Glyndwr "held parley, and made his covenant." The boulders are on the north-western slope of Plynlumon, 100 yards above the right bank of the river Hyddgen [..] Each stone is 2 feet high, and shows no trace of tooling. They are 60 feet apart and are aligned exactly north and south. Though not placed in an elevated position, they can be seen from afar, and show up conspicuously in the sunlight.