Former Istrian coal mine reopened as an immersive underground tourism attraction with a mining museum in the purpose-built fascist-era town of Raša.
Rudnik Raša is a coal mine in eastern Istria, Croatia, whose recorded history extends to the seventeenth century, with the earliest known concession granted in 1626. Scaled-up industrial extraction under Italian administration from 1928 saw the workforce grow to more than ten thousand miners producing high-calorific anthracite coal notable for its exceptionally high sulphur content, which reached up to fourteen per cent. The coal company financed the construction of the purpose-built miners' town of Raša, completed in 1937 to designs by Trieste architect Gustavo Pulitzer-Finali.
Production at the mine ceased in 1966. The flooded underground workings extend to more than fourteen kilometres of corridors, with some sections descending to three hundred metres below sea level. Following municipal investment of €870,000, the mine reopened in July 2023 as the Kova Experience, an immersive underground tourism attraction, with 1.5 kilometres of the Karlota adit made accessible to visitors alongside a dedicated mining museum.
Coal mining in the Raša area of eastern Istria has a documented history reaching back to the period of Venetian administration. The earliest known concession for coal extraction dates to 1626, and modest artisanal production continued across subsequent centuries. By the time of Austrian administration in the late nineteenth and early twentieth century, around 1,500 workers were extracting approximately 90,000 tonnes per year from the Krapan area, and a small church dedicated to the miners' patron saint Barbara was built in 1905 in the form of an inverted coal wagon with a bell tower resembling a miner's lamp.
Industrial extraction under Italian rule expanded significantly, and by 1936 output had reached 735,610 tonnes annually. The coal-mining company Arsa Società Anonima Carbonifera and its successor, Azienda Carboni Italiani (A.Ca.I.), financed the construction of a completely new settlement to house the growing workforce. The miners' town was built within 547 days between April 1936 and April 1937 when the first residents moved in.
Designed by architect Gustavo Pulitzer-Finali of Trieste according to rationalist principles, it was organised along a linear axis with residential zones for ordinary miners, senior miners, and executive villas, together with a central square, hotel, post office, cinema, pharmacy, and administrative buildings. The town was named Arsia in Italian, subsequently Raša in Croatian, after the nearby river. The mine employed more than ten thousand workers between 1928 and its closure in 1966.
The coal extracted from the Labin basin was notable in world terms for its high organic sulphur content, which reached fourteen per cent in some analyses and created both environmental and commercial difficulties, particularly in selling the smaller grades. This issue was a principal factor in the decision to close the mine in 1966, though a subsidised exploration programme and new mine construction was undertaken in 1976 in an effort to resume extraction. In 1987 a final decision was taken to discontinue further investment owing to the complex micro- and macro-tectonics of the deposit, the small quantities of recoverable coal, environmental concerns related to the high sulphur content, and the risk of seawater intrusion.
A saline groundwater breakthrough had already been encountered as early as 1934 when a mine gallery struck a water-bearing cavern at 140 metres below sea level some 3.5 kilometres from the Adriatic coast; the inflow was sealed with a concrete plug, but the event foreshadowed the long-term hydrogeological difficulties of the field. Gradual closure followed between 1987 and 1989, and flooding of the mine began in 1988, concluding in May 1991 when water began discharging freely from mine galleries into the sea. The underground workings of the Raša coalfield cover a technological landscape of more than 200 square kilometres, with over fourteen kilometres of underground corridors and coal-bearing beds up to 400 metres thick.
Parts of the mine reach 300 metres below mean sea level. Post-closure, the town of Raša became recognised as a rare and well-preserved example of Italian rationalist industrial town planning from the interwar period. Following several years of preparatory work and documentation, the Municipality of Raša invested €870,000 in converting the former mine for tourism.
Renovation lasting approximately eighteen months stabilised and illuminated the Karlota adit and connected underground gallery. The Kova Experience opened on 17 July 2023, offering guided tours through 1.5 kilometres of accessible workings including the underground machine room with original haulage equipment, two blind shafts, and the junction of the Karlota and Raša adits. A mining museum, the Kovarska kuća Arsia, was established in the town square, comprising two sections: one reconstructing mine working conditions with authentic tools, photographs, and film footage, and the other a replica of a typical miner's apartment.
The Kova Experience is the only accessible coal mine in Croatia.