Evidence of mining remains around Caeau Farm in the form of grassed-over shafts and mounds, which align in two north-west to south-east lines on either side of the farm. The largest shafts are located at SJ 1960 7295 and SJ 1970 7295. Two additional shafts are present to the northeast of Dafarn-Dywll at SJ 1950 7275.

Smith (1921) mentions the Caeau Engine Shaft and a whimsey at a separate drawing shaft. The Rhyd-Fudr Mine appears on the 1914 6“ OS map, though no visible remains exist today.

The Caeau, Rhydfudr, and Llongle Mines worked the Pantypedw Vein between 1834 and 1848 but were abandoned due to water ingress and poor ventilation. Between 1910 and 1912, the Holywell-Halkyn Mining and Tunnel Company reopened the site, working the New Caeau Mine beneath the old workings, approximately 230 yards east of Caeau Farm. During this period, the Caeau Engine Shaft was deepened from 124 yards to 141 yards through chert beds. The mine was unwatered via an incline rise to the Milwr Tunnel (Smith 1921).