1. Lewis Merthyr Colliery was established by W.T.Lewis (Lord Merthyr) in the mid 1870s and closed in 1983. Now incorporated into the Rhondda Heritage Park, the colliery is one of the best surviving in South Wales and includes two early examples of headgear, erected over the Bertie and Trefor shafts. The associated winding houses (Trefor to the east, dated 1878 and Bertie to the west, dated 1890) are constructed of rusticated ('bull-nosed') pennant sandstone. To the east of the engine-houses is the tall tapering yellow-brick chimney (nprn 33495) built on a bull-nosed pennant sandstone base.
B.A.Malaws, RCAHMW, 22 January 2001.

2. Originally Coedcae Colliery, later Lewis Merthyr Navigation Collieries, later Lewis Merthyr Consolidated Collieries, sunk in the 1870s and closed in 1983. Buildings include the two oldest headframes remaining in Wales, two winding-houses, with an electric and a steam winder, complete pitheads, an old lamproom (nprn 33497) and two fan houses. Trefor Shaft (Winding House dated 1878) ceased production in 1958 and Bertie Shaft (Winding and Compressor House dated 1890) ceased production in 1960. Situated between the two shafts are the later lamproom (nprn 33496) and fanroom. The site is now administered by the local authority and open to the public.
(A Guide to the Industrial Archaeology of South East Wales, AIA, 2003)
The pithead baths (nprn 90) stood on the opposite (north) bank of the Rhondda River but have been demolished.
B.A.Malaws, RCAHMW, 03 June 2010.