IF ASKED to name the richest square mile in the world today you would probably come up with somewhere like the City of London, Silicon Valley or Jwaneng diamond mine in south-central Botswana. The same question asked nearly two centuries ago would have produced a very different answer and identified a location much closer to home. Between 1820 and 1840 an area of land in the parish of Gwennap, near Redruth, was known as "the richest square mile in the Old World" and yielded a significant proportion of all the copper produced in the world. It was an area that stretched from Crofthandy to Hale Mills Valley and from Carharrack to Sunny Corner, and included Wheal Maid, Consols and United mines. Local historian Eric Rabjohns said: "These years saw this area becoming the greatest and the richest in the mining world, with Carharrack emerging as a village from a cluster of dwellings. "From 1819 to 1940, Consolidated Mines yielded close to 300,000 tons of copper ore, which sold for £2 million (worth more than £100 million today."