Henllys Vale Colliery is now a ruinous colliery site with a tall brick built boilerhouse chimney stack and a bank of associated limekilns. The colliery was part of an anthracite drift which operated from 1898 to 1918. The kilns were used with local coal from the 1880s. The Ordnance Survey County series mapping (Carmarthen. L.1 1878) shows a single coal level in this vicinity. An incline (NPRN 308738) links a limestone extraction complex at Foel Fraith (NPRN 84199), presumably with the kilns at this location.

If the site is approached on foot from Brynhenllys bridge, there is a path that follows the former railway line, and between the path and the River Twrch there are sections of leat which fed water to the lower Brynhenllys colliery for operating pumps and screens. The colliery closed in 1955 and there are some modern remains.

Sources:
Collieries of Wales, RCAHMW
A Guide to the Industrial Archaeology of the Swansea Region, by Stephen Hughes and Paul Reynolds, AIA, 1989

Claire Parry, RCAHMW, 24 August 2011