LLAN-RHAIDAR-YN-MOCHNANT, a large parish of Wales, in the county of Denbigh and hundred of Chirck. It is situated in a deep hollow, and surrounded on every side by lofty mountains. It is much frequented by visitors, who go to it to get a view of the celebrated water-fall of Pistell-Raiadr. It is 224 miles from London. The population amounted in 1801 to 1869, in 1811 to 1974, in 1821 to 2229, and in 1831 to 2344.