Chile's coal is confined to a few places in the country's southern half, and the historic heart of the industry was the Arauco Basin around the mouth of the Biobío River. People here had burned local coal since at least 1557, when, according to the chronicler Diego de Rosales, the governor García Hurtado de Mendoza stayed on Quiriquina Island. For centuries it stayed a curiosity. Early British travelers could not even agree on its worth: David Barry judged the coals good, while Charles Darwin, passing through, found them of little value. The British consul saw further. In 1825 he predicted that the area around the Biobío's mouth would become a center of the coal industry, and within a few decades, during the mid-19th century, large-scale mining proved him right.

Mining the Arauco Basin was brutally hard. The coal seams were less than a meter thick and broken up by a dense web of geological faults that shoved the beds out of alignment, which made the work nearly impossible to mechanize. So it was done by hand, by men, deep underground and far out beneath the seabed. The conditions at Lota became a byword for exploitation. In 1904 the Chilean writer Baldomero Lillo, who had grown up in the coal country, published Sub Terra, a collection of stories that laid bare the suffering of the miners and forced the rest of Chile to look at what the fuel cost. The book made El Chiflón del Diablo famous as a place of danger and grinding injustice rather than industrial pride.

The coal towns were strongholds of Chilean labor and the political battles that came with it. Discontent ran deep, and the miners' loyalties were strongly socialist. In the early 1970s, amid civil unrest and that heavy socialist support, President Salvador Allende nationalized Lota's mines, bringing them under state control. After the 1973 coup, the military government of Augusto Pinochet reversed course and privatized them again. The pits themselves did not care who owned them. The same thin seams, the same faults, the same sea overhead remained, and the men still went down each day to work them by hand in a country whose politics convulsed around their heads.

Large-scale coal mining in the Arauco Basin came to an end in the 1990s, and the great undersea works at Lota fell silent. Other deposits had their day too, from the small mines of the Los Ríos region with names like Catamutún and Pupunahue, to the far southern Magallanes pits near the Strait of Magellan. But the decline did not erase the identity that coal had forged. The communities of the zone, the Wikipedia record notes plainly, continue to identify with it. Lota's old works survive as heritage, and the very tunnels that once meant darkness and risk now draw visitors, sometimes guided by the former miners themselves. They walk newcomers under the same low ceilings where they spent their lives, telling stories of the camaraderie and the danger of working coal beneath the Pacific.