SS66019649 to SS66429642. A raised embankment (around 40ft wide) running obliquely east down Graig Trewyddfa suggests that the most northerly of the Cnap Llwyd sandstone quarries may once have had a self-acting railway. There was, however, no hint of this in 1838 (Hughes, 'Copperopolis', pp. 307 and 316).