Great Hewas Mine, also known as Hewas Downs Mine or Great Hewas United, along with Ventonwyn Mine, worked in conjunction with Kingsdown or Hewas Water Mine. Operating since the 1790s, Great Hewas Mine ceased operations in 1926. It exploited several lodes for lead, silver, copper, and tin. Ventonwyn Stamps engine house chimney serves as a prominent landmark on a ridge north of the Truro to St. Austell road. Ventonwyn Mine, previously called Wheal Elizabeth, was a small tin mine located about half a mile northwest of Hewas Mine, operational from 1903. It also collaborated with the nearby Great Dowgas Mine. Production records include: Hewas (from 1821) - 482 tons of 5.75% copper ore; Great Hewas (from 1856) - 19 tons of 64% lead ore and 48 ounces of silver; Great Hewas United (1854-60) - 867 tons of black tin; and Kingsdown (Hewas Water) Mine (1919-26) - 24 tons of black tin per month.