GWILLER, a township, joint with Trewern, in the parish of LLANVIHANGEL-NANT-MELAN, within the liberties of the borough of
NEW-RADNOR, county of RADNOR, SOUTH WALES, 2 miles (S. W.) from New Radnor. The population is returned with Trewern. The
parish church is situated in this township, which occupies a small vale in the southern portion of the mountainous
district called Radnor Forest, near the source of the Sommergild brook. Here is also the celebrated cascade called " Water
break its neck," which is formed by a stream that rises in the above-mentioned district, and, after a fall of seventy feet
perpendicularly, joins that brook. The lower portion of the township is well wooded; and there is a lake, termed L15n
Llanillyn, about three-quarters of a mile in circumference.