Streams are rare in the district and their value to industry is exemplified in the Kenidjack Valley which contains a remarkable concentration of industrial remains. Where the valley meets the sea, Porthledden Cove is dominated by views to Cape Cornwall but in the valley itself the river course has been repeatedly moved and numerous manmade watercourses (leat systems) skirt the hillsides.

Kenidjack Valley. The entire valley bears extensive evidence of mining. The Kenidjack stream once powered up to fifty waterwheels. When steam engines were installed lower down the valley, two out of five only operated during periods of prolonged dry weather.

Kenidjack arsenic works. These works contained a furnace that was the precursor to the Brunton calciner. Most of the surrounding walled structures contained waterwheel-driven crushing mills.

Boswedden Mine (Wheal Call). In 1837 the Wheal Call ‘Great Wheel’ was the second largest in Britain at 65 feet diameter (19.8 m). The extant masonry wheel pit in the lower Kenidjack Valley (left) was enlarged around 1865 to accommodate a waterwheel of 52 feet (15.8 m).