The Jamaica Mine is located on the flat layers of Cefn-y-Fedw Sandstone, with the outcrops visible near America Farm (SJ 2130 6085). A series of at least twelve large shafts, open workings, and spoil heaps stretch from SJ 2180 6100, extending westward toward the Maeshafn Mine (SJ 2040 6105). The Jamaica workings crossed paths with the Maeshafn Vein.
