Coal was first reported near Muara as early as 1837, in the area known as Serai Pimping. For decades the deposits remained little more than a geological curiosity, noted by surveyors but unexploited in any serious commercial sense. The Sultanate of Brunei, once the dominant power across Borneo, was by the mid-nineteenth century contracting under pressure from the British-backed Brooke dynasty in Sarawak and the chartered companies carving up the region. Resources that might have enriched the sultanate instead became bargaining chips in a landscape of competing colonial interests. It would take nearly half a century after that first coal report before anyone struck a deal to dig.

In 1883, a Scottish merchant named William Cowie secured the concession rights to mine coal at Muara for the sum of $1,200 per year. Cowie was no stranger to profitable ventures in the region -- he had built his fortune running arms and supplies through the contested waters of Southeast Asia. But the coal operation proved less suited to his ambitions, and he eventually sold his rights to Rajah Charles Brooke, the second White Rajah of Sarawak. Brooke, who governed Sarawak as a personal kingdom, promptly renamed the mine Brooketon -- literally "Brooke Town" -- stamping his family name onto the Bruneian landscape with the casual possessiveness that characterized the era. From 1889, the Sarawak government operated the mine directly, turning it into a reliable if modest export concern.

Between 1889 and 1924, the Brooketon Colliery shipped coal steadily from its underground workings. Annual exports fluctuated between 10,000 and 25,000 tons, a modest output by global standards but significant for the region. Over those thirty-three years of operation, more than 650,000 tons left the mine -- carried by rail to the coast, loaded onto ships, and dispersed across the trading networks of colonial Southeast Asia. The mine employed local workers alongside imported laborers, and the settlement that grew around the colliery reflected the mixed populations typical of extractive operations throughout Borneo. When the mine finally closed in 1924, the reasons were economic rather than geological: the seams still held coal, but shifting markets and the rising dominance of petroleum made continued operation unviable.

The jungle reclaimed Brooketon quickly. Within a generation, the mine's surface works had been swallowed by the dense tropical vegetation that characterizes Brunei's coastal lowlands. But the site's historical significance was not forgotten. Brunei's Museums Department identified the 62-hectare colliery as a candidate for an open-site museum, envisioning a place where visitors could walk the remnants of the country's pre-petroleum industrial history while surrounded by the rainforest that has reasserted itself over the old workings. The site is now protected under the Antiquities and Treasure Trove Act of Brunei Darussalam, ensuring that the mine's infrastructure -- what remains of it -- cannot be disturbed or developed. In a country where oil and gas have dominated the national story since the 1920s, Brooketon stands as a quiet corrective: Brunei's relationship with extractive wealth is older and more complicated than the petroleum narrative suggests.