The relatively unknown Llanengan metal mining field is found on the St. Tudwal's headland, on the tip of the Lleyn Peninsula, North Wales. Its isolated position meant that it never was given the same publicity as many of the major metal mining areas. Nevertheless it was a hive of activity in the latter half of the 19th century, and the mines were deepened with the aid of steam power, used for pumping water out of the workings, and for winding ore to the surface. Everything, from mine engines to coal was brought into the area on ships. The book details the history of mining in the area from the 17th century through to its eventual demise at the end of the 19th century. Initially mining was conducted by partnerships that were eventually superseded by London based companies that acquired capital to purchase the necessary machinery to deepen the mines. Now there is very little to show that this area was once a hive of industrial activity, although the final chapter does suggest a small heritage walk around the area. For a number of years, John Bennett and Rob Vernon were involved with the historical study of Welsh metal mining. Their series of seven detailed books on the Gwydyr Forest mines was a substantial contribution to the recording of Welsh mining history. In addition, they were also involved with mine site conservation projects in the Gwydyr Forest and elsewhere in Wales. John sadly died in 2019, and Rob is now involved with other aspects of mining history. At the time of the publication of the first edition of Metal Mines of Llanengan in 2002, it did take their interests further and brought into the public domain a relatively unknown Welsh mining area. The publication of this second edition will hopefully make another generation of mining historians aware of this interesting mining field and is dedicated to John and his wife Elizabeth.