History: Serra Pelada Gold Mine, Pará, Brazil

Discovery
In January 1979 Farmer Genésio Ferreira da Silva hired a geologist to investigate whether gold he found on his property was part of a larger deposit. A local child swimming on the banks of a local river found a 6 grams (0.21 oz) nugget of gold. Soon word leaked out that indeed da Silva was sitting upon one of the largest deposits in the world. By the end of the week a gold rush had started with thousands of people descending on the farm to mine. Five weeks later, there were 10,000 on Ferreira's property and another 12,000 nearby. Huge nuggets were quickly discovered, the biggest weighing nearly 6.8 kilograms (15 lb), $108,000 at the 1980 market price. ($108,000US is now $ 300,926 in 2013)
At first the only way to get to the remote site was by plane or foot. Miners would often pay exorbitant prices to have taxis drive them from the nearest town to the end of a dirt track; from there, they would walk the remaining distance—some 15 kilometres (9.3 mi) to the site. The growing town, since it could only be made of material that was carried in by hand, was a collection of haphazard shacks and tents. Each miner had a claim 2 metres (6.6 ft) by 3 metres (9.8 ft). By May 1980 there were 4000 such claims.