In the heart of the Sierra Morena, and at some twelve kilometres as the crow flies to the north-west of the modern town of La Carolina, in the province of Jaen, a silver-lead mine is at present being successfully worked by an English company. But the English company would not be working it to-day, nor would they be doing so successfully, were it not for the fact that the Romans had been there before them and that the Roman miners had left indications on the surface that pointed to extensive workings below, and had not exhausted the riches which kindly Nature had stored in the vein which they exploited. That the Romans must have worked the mine which is known in our times as “el Centenillo” during a long period is principally evidenced by the extent of their underground operations, which attained the astonishing depth of 210 metres (690 feet) from surface, while in length they exceeded a thousand metres (3,280 feet) and gradually narrowed down in depth until, for some reason that will never be known and which it would be imprudent to guess at, the “old men” abandoned the mine. They worked on the best part of the lode which, in all probability, resembled other lodes in the district in being richer in silver near the surface. The Romans must, however, have been principally working the mine for lead when they determined to leave it, as their lowest workings were in a highly mineralised zone which was very good for galena but relatively poor in silver; although, as a matter of fact, the mineral, even at the depth of 325 metres (1,066 feet) which has been attained to-day, carries more silver than the other silver-lead mines of the district. (The galena contains about 82 per cent, of lead and yields about 20 ounces of silver to the ton.)