Worked eastern end of Pant Vein. 19C Engine Shaft is only surviving feaure.

Maeslygan was among the earliest mining sites established by the Governor and Company for smelting lead using pit and sea coal. This development followed the company’s receipt of a Royal Charter in 1694. During its operation between 1692 and 1728, the mine was part of a larger network owned by the Quaker Company, as it later came to be known. A sketch plan from this period includes Maeslygan among its holdings.

The mine primarily extracted lead from the eastern section of the Pant Vein. Today, the only visible remnant of these operations is the Old Engine Shaft, a 19th-century structure located at SJ 2050 7220, southwest of the Springfield Hotel. The most productive area within this mining concession was Cae’r Bryn Bychan Field, also referred to as Rhodes. Additionally, a mid-18th century tunnel, driven from near Plas Isaf at SJ 218 720, was recorded but has yet to be located.

Maeslygan played a role in early industrial advancements, with one of the first Newcomen steam engines reportedly operating on the site during the 1730s. All extracted ores were transported to Flint, where the Quaker Company processed them at their Gadlys smelting facility.