Gold was the initial draw. By the 16th century, prospectors knew the Yaracuy, Santa Cruz, and Aroa rivers carried gold, and in 1605 deposits were found in a small valley near the Aroa River. The King of Spain granted the mines in perpetuity to Dr. Francisco Marin de Narvaez and his heirs in exchange for 40,000 pesos. When mining began in 1632, workers following gold veins discovered something far more abundant: copper, in quantities that would sustain operations for centuries. The mines attracted the indigenous Gayones people from the Duaca region, 40 kilometers to the southwest. They came partly for wages, but also because the mines offered something unexpected -- a place to practice their traditional religion without interference from Catholic priests, who held less sway in the remote mining camps than in the settled towns.

Around the end of the 17th century, the Cobre Caracas mining company passed into the hands of the Bolivar family. The largest mine, La Vizcaina, was worked by 60 to 70 enslaved people, and copper production surged through the 1790s. When Simon Bolivar inherited the family holdings, the mines became an asset of revolution. In 1824, Bolivar leased them to British entrepreneurs -- some sources say explicitly to fund the struggle for independence from Spain. Captain Joseph Malachy sailed from Plymouth in March 1825 to serve as resident director, earning the enormous salary of 1,200 pounds at a time when Cornish mine managers made roughly 300. The British employed about 1,200 workers, shipping ore down the Aroa River by barge to the coast. After Bolivar's death in 1830, his sisters Juana and Maria Antonia sold the mines to Robert Dent, the Englishman who ran the Bolivar Mining Association.

In the 1830s, Cornish miners in the reduction department made significant advances in methods of calcinating copper ore, but the operation struggled. High mortality among European workers -- the warm, humid climate was brutal on men accustomed to Cornwall's temperate coast -- and tensions with local laborers forced a temporary closure in 1836. A young English engineer named John Hawkshaw was sent to plan a railway from the mines to the port of Tucacas, but the climate defeated him too, and he returned to England in 1834 before eventually becoming one of Britain's most celebrated civil engineers. Decades of civil wars and operational difficulties delayed the railway until 1877, when a narrow-gauge line finally opened. The Ferrocarril Bolivar was the first railway in Venezuela. In 1891, it was extended from Aroa through Duaca all the way to Barquisimeto, and Aroa became the first town in the country to receive electricity and telephone service.

The mines changed hands through a succession of British companies -- La Quebrada Land Mining Company, Aroa Mines Limited, the South American Copper Syndicate. By 1930, six mines were in operation: Aroa Norte, Titiara, Titiara Norte, San Antonio, Zajon Verde 1 and Zajon Verde 2. The longest tunnel, Titiara Norte, reached 2,100 meters; the deepest, Aroa Norte, descended 95 meters underground. But in 1936, the last company abandoned the operation. The Venezuelan state acquired the mines in 1957 and transferred them to the Petrochemical Institute for pyrite and copper carbonate extraction. In 1974, the 9,000-hectare Parque Minas de Aroa was established around the old workings. Today the tunnels are partially flooded, and thick forest has reclaimed the hillsides. Visitors can walk among the ruins of the mining camp, the copper smelter, the railway, and a quiet English cemetery where some of the Cornish miners were buried far from home.