Evidence from the fortification (known as Luentinum from details given in Ptolemy's "Geographia") and its associated settlement show that the Roman army occupied the fort from to . However, coarse ware and Samian ware pottery recovered from a reservoir (Melin-y-Milwyr) within the mine complex show that activity at the mines continued until the late 3rd century at least. Since Ptolemy's map dates to about 150, it is likely that it continued being worked until the end of the 3rd century if not beyond.