The Wemyss mine was a lead and zinc mine which operated in conjunction with Frongoch Mine (nprn 302), working the Frongoch lode intermittently from 1861 to 1899, together with West Frongoch. In 1899 a dressing mill (nprn 33870) was built on the site to process ore from Frongoch Mine. A fine wheelpit and remains of the dressing mill survive.

RCAHMW, 07 January 2008.