The ecclesiastical parish of Pembrey is one of the largest in the county, extending from the Burry River to the Gwendraeth Valley, and comprising an area of 21,714 acres. Coal bearing rocks occur throughout the parish and in low lying areas they are overlaid by alluvial matter and deposits of sand.  Owing to the case with which coal could be worked on these outcrops, mining operations were carried out at an early date, but these first efforts in the industrial life of the district were on a very modest scale. The coal was worked by means of adit levels , affording free drainage and from shallow pits.

The methods of working were naturally primitive. very few men worked in each mine, as ventilation , lighting and transport were difficult. Boys were often employed to carry the coal on their backs in small baskets underground. Yet the old miners were most skillful, considering the scanty appliances at their disposal. Their roadways were so well made that traces of than were in existence for over a century. At an old pit near Achddu some wooden water pipes were discovered. The Gwendraeth Fawr river was tidal to Spudders bridge and high tides covered the low-lying marshes adjoining. There was a loading place near Park-y-llong, and another near the present aqueduct, where Trimsaran coal was loaded. At the latter place there was a small dry dock as well. On low lying lands between Pwll and where Burry port now stands, which were intersected by small pills or creeks, were also covered by high tides. There were small loading places on these pills, and at high tides small crafts were able to go a good distance.

The coal was conveyed from the mines to the seaboard by pack horses along the roads, and subsequently along narrow gauge tram roads. Small boats conveyed coal to the Gower, The ballast for the return cargo being limestone. There were kilns for lime-burning near every loading place. The conditions previously described remained in force until about 1750, when the industrial age commenced. Ay that point Pembrey was a tiny village around its ancient parish church. It was almost cut off from the adjoining district, the main approach being over the mountain road.