Sydenham Damerel: grid reference SX424769

Otherwise known as Collacombe Down, the mine includes Wheal Grace, Wheal Conquer and Devon Mine. Situated to the northeast of Sydenham Damerel near Tavistock, Wheal Grace occupied the west of the sett, Wheal Conquer the central section while Devon Mine occupied the east of the sett. Underground plans survive only for Devon Mine and indicate that North Lode, Main Lode and Middle Lode were worked from Morris' Shaft, Western Shaft, Old Engine Shaft and Old Whim Shaft. The mine produced copper, lead tin, wolfram, fluorspar and zinc.

Production records report that Wheal Conquer raised 1,700 tons of 80% lead containing 15 oz. of silver per ton as well as 1,400 tons of copper ore. Collacombe produced 8,502 tons of copper ore. Further records state that Wheal Conquer produced 64,456 tons of 6.75% copper between 1845 and 1889; 5 tons of 63% lead ore and 65oz. of silver in 1862; 24 tons of black tin in 1906 and 1909-13. In 1855 and between 1869-1911 over 12,960 tons of mispickel was raised. In 1875 and between 1878-79 59 tons of fluorspar was produced. 35 tons of wolfram (tungsten) was produced between 1900 and 1913.