Tavistock: grid reference SX437677

Known over the years by a number of names including New Tamar Valley Mine, Green Valley Mine, Wheal Fancy and Bere Alston United Mine, Buttspill Mine lies just to the south of Calstock on the Devon (eastern) side of the River Tamar. The mine is thought to date from Elizabethan times. It was reopened in 1843 as Green Valley Mine but shortly after renamed Wheal Fancy by new owners. The mine was reopened again as Berealston United Mine in 1855 and it was worked mostly on the 17 and 27 fathom levels. A smelter was erected but production focused mostly on the high quality fluorspar.

Its main shafts were Western Engine Shaft and Engine Shaft.

In his book of 1956 entitled 'The Metalliferous Mining Region of South-West England (Vol.II) historian H.G. Dines states that: 'Outputs in 1870-76 were 95 tons lead ore, 650 ounces of silver, 20 tons pyrite and 620 tons of fluorspar. In 1885-6 as Tamar Valley Mine, 90 tons of fluorspar was produced'.