Set 43km (27 miles) north of the bustling port city of Makassar, on the Indonesian island of Sulawesi, its official name is Maros Pangkep Global Geopark, though locals call it Rammang-rammang, the word for “clouds” in the Makassar language; thick fog clouds the area at dawn and when it rains.

The story of how Rammang-rammang became an ecotourist attraction is a story of David and Goliath.

The drama goes back to 2005, when the Maros district government issued permits for a dozen mining companies to extract Sulawesi marble, a rock renowned for its patterns and colour that is in demand around the world.

Coupled with a cement factory established on the edge of the park, these industries appeared to spell the end for Rammang-rammang as a place of natural beauty – until a grass-roots campaign flipped the script.

Nasrul, who like many Indonesians goes by only one name, was part of the campaign; today he manages a small guest house called Nasrul House, on the second floor of his parent’s home.

He has four beds, cordoned by curtains, to rent for 250,000 rupiah (US$16) per night. Meals of fish, vegetables and rice are shared with Nasrul’s family, as is the only bathroom in the house. The place is rustic but charming and the conversation is intriguing.

“That karst,” Nasrul says, pointing to one of the largest rock formations, “is very important to us. We call it Sacred Mountain because we believe the spirits of our ancestors live there.”

Like many of his neighbours, Nasrul was initially in favour of mining the karsts.

“When the mining companies arrived, they promised all of us jobs,” he recalls. “I thought that was good because there were no jobs here at the time.

“But I didn’t understand the impact of mining. Then I got educated and started to understand nature is not just for us to smash and sell, but for future generations. So I joined a group, Youth River Community, that made contact with politicians, got advice from NGOs and spread awareness on social media.

“Then we began thinking about how we could make money without mining the karsts and decided on eco-tourism. If you destroy nature, you have nothing left. But if you do eco-tourism, you get to keep the nature, and get money.”

In 2013, the campaign bore fruit when the Maros government revoked various mining permits and issued a moratorium on new mine sites. Two years later, the Rammang-rammang eco-tourism area was born, employing 200 residents in conservation, education, organic farming and the development of local cuisine.

In 2017, the Maros-Pangkep Geopark was gazetted by the central government in Jakarta and a proposal was lodged with Unesco for Global Geopark status.

By 2019, visitor numbers peaked at 50,000 per year, according to Statistics Indonesia. Tourism died out during the pandemic but is steadily coming back, with about 2,000 people, nearly all of them Indonesian, visiting Rammang-rammang every weekend during the dry season, between June and November. Weekdays are much more quiet.

The best way to see the karsts is on small wooden boats, the pilots of which charge 200,000 rupiah to take visitors on a 20-minute cruise along a caramel-coloured river that cuts through thick green jungle teeming with bird life, black monkeys and at least 240 known species of butterfly.

Rammang-rammang, our boatman says, is nicknamed Kingdom of Butterflies.

After passing through a tunnel at the base of a limestone cliff, boats enter a hidden world that is home to the tallest and most dramatic karsts in the park.

Shaped by water over 30 million years and rising to 100 metres (328ft) above the ground, they are testament to the grandeur of the natural world.

The journey reaches an end at Berua (“new” in the Makassar language), a village inhabited by 15 farming families who live in stilt houses and sell drinks and snacks to visitors to supplement their incomes.

The elevated wooden walkways that weave through emerald green rice paddies planted between the karsts have made Rammang-rammang an Instagram hit.

The karsts occupy 43,000 hectares (106,255 acres) – more than half the footprint of Singapore. But only 23,000 hectares are protected by the geopark; the remaining section continues to be degraded by extractive industries.

The heavy excavation equipment of 30 official mines roars along the road connecting Rammang-rammang to the prehistoric caves, while, in hundreds of small pits, locals who haven’t benefited from tourism chip away at the karsts with hand tools

“If uncontrolled mining activities continue, not only will the karst area be destroyed … in the end, it will be the community that will suffer the consequences,” Al Amin, executive director of Walhi Sulsel, an NGO in Sulawesi, told Indonesian news site Kompas.

He urges authorities to put an end to mining at Rammang-rammang once and for all, lest Unesco revoke its Global Geopark status.

According to Unesco’s website, Global Geopark designations have a shelf life of four years, “after which the functioning and quality of each geopark is thoroughly re-examined during a revalidation process”.

For Nasrul, the solution is more eco-tourism.

“Tourism is so much better than mining,” he says. “Local people can work as boat drivers, as tour guides or open homestays like mine. People not working in tourism who just rely on nature to survive can fish, forage in the forests to survive because they’re not covered in mine dust.

“I hope in the future more people will come here and spread awareness about the importance of protecting the karsts.”