In the 20th century, Bogotá was one of the fastest-growing cities in the world. The Colombian capital’s population increased at a staggering rate, from just 330,000 in 1938 to 5.5 million in 2000. That exponential growth was fueled by the rapid modernization of its infrastructure and economy—as well as an explosion of violence in rural areas that drove people to the city. For several years, Colombia had the tragic distinction of having the world’s highest number of internal refugees.

As the city’s population swelled, it needed buildings and roads to match. Enter La Siberia, a company town and cement plant owned by the Samper company where, from 1933 to 1999, much of Bogotá was produced. Located about 12 miles outside the city, near the town of La Calera, the abandoned complex sits at about 9,000 feet above sea level, surrounded by the wilderness of the Chingaza páramo. At its peak, La Siberia produced 1,000 tons of cement daily. It was home to more than 80 families, and included a church, school, police station, and cemetery, all in the shadow of three enormous, cylindrical cement ovens.

The factory was shut down in 1999 amid a nationwide economic crisis, following complaints from residents about pollution and the environmental impact of limestone mining. Today, it’s owned by a Mexican multinational and sits in a state of disrepair. The walls are covered in graffiti, the empty workers’ homes are crumbling, and the vegetation of the High Andes is gradually encroaching on the site, reclaiming the pocket of industry once carved out by the limestone miners.

Rumors of ghosts abound: Priests have done exorcisms, a journalist reported hearing a children’s choir, and many more visitors have seen lights in windows or mysterious figures on the move. Groups of bogotano youth once made a habit of heading to the site at nighttime to search for spirits, make art, and throw spooky parties; today, the owner employs a full-time watchman to ward off ghost-hunters and mischief-makers.