In 1922, a trial was conducted to explore an extension of the South Terras uranium lode. The operation involved driving an adit eastward from the valley of the river Fal and sinking a shaft that connected to the adit at a depth of 75 fathoms from its entrance. Short levels were driven to the north and south from where the lode was anticipated, but only barren quartz strings were encountered. Continuing beyond the shaft, the adit intersected with an elvan, leading to the influx of radioactive water into the workings. Since the lode wasn’t found, the operation was abandoned at a depth of 133 fathoms from the adit entrance. Today, the workings are completely concealed, with the grid reference marking the approximate location of the adit portal.