Hundreds of feet under Transylvania lurks a gaping hole where undulating layers of black, white, and gray wind along rocky subterranean walls. Millions of years ago, a sprawling sea once blanketed the region of Romania where this cavern now lies. But the water has long since dried up, leaving behind the mineral that gives the cave walls their stripes: salt.
This saline secret was a boon for the region and was mined for hundreds of years, starting as early as 1075. As miners extracted the mineral, they dug the magnificent cavern, expanding it until the mine, known as Salina Turda, closed in 1932. Now, the subterranean space has a fresh purpose, delighting visitors as an underground amusement park.
This is just one example of an industrial site reimagined for public use. National Geographic photographer Luca Locatelli became enchanted by these sites while documenting the so-called "circular economy," a vision of the future where little is wasted and reuse reigns. "Land is a finite resource," he says.
The scars from industrial activities take decades or more to remediate—and some sites, like Salina Turda, are irreparably changed—making repurposing a vital way to conserve Earth’s limited resources.
In some cases, repurposing also gives new use to contaminated landscapes and draws attention to the environmental risks of many industrial activities. For example, Locatelli also photographed Ferropolis, an old open pit coal mine near the city of Gräfenhainichen in Germany. Though the grounds have been cleaned and capped in concrete, the fingerprints of the coal industry are undeniable.
In Locatelli’s images, visitors dance under colored lights, surrounding the monstrous machines once used to reap our planet’s resources. Now the towering mining equipment stands like sentinels among the crowds, a reminder of the site's history and hope for a greener future.