Nant Hir Level workings comprised of six levels (NPRNs: 516252; 516554; 516553; 516556; 516555 and 516867), an air shaft (NPRN: 516552), smithy (NPRN: 516534), as well as the remains of associated buildings (NPRNs: 516549 and 516550). The workings are denoted initially on the Ordnance Survey County Series mapping of 1876 (Glamorgan, XXVI 7) as Coal Level and Air Shaft, which by 1899 had expanded to include a tramway, smithy and engine house. By 1919 they are disused.

Photographed during aerial reconnaissance by RCAHMW on 16th October 2008.
L. Osborne, 5th December 2012.