"I decided to experience the real Jakarta," said a tourist, stepping gingerly between puddles of putrid water and a scurrying rat in a scene that would never make a postcard.
Rohaizad Abu Bakar, 28, a bank employee from Singapore, said he could not believe his eyes as he wandered around the slum in the Indonesian capital, a jumble of hundreds of shacks, some less than a from a railway line.
Nearby, a small girl picked up a discarded juice bottle in search of a sip while a man wearing tattered shorts lay slumped on a dirty old mattress. Only a blue plastic tarpaulin offered shelter from tropical downpours.
So-called poverty tourism is on the rise in Jakarta.
Organizers say it raises awareness and brings aid to the destitute of the city, but accusations of exploitation are never far away and critics say poverty should not be a tourist attraction.
A few hundred families cram into the slum in the Tanah Abang neighborhood, minutes from gleaming shopping malls where the likes of Gucci and Louis Vuitton compete to lure the newly minted beneficiaries of Indonesia's economic miracle.
Abu Bakar opted against the picturesque landscapes of other parts of the country to instead join a "Jakarta Hidden Tours" trip, which aims to show visitors the squalid conditions of the nation's poor.
"Tourists stay in their ghetto. We show what is really Jakarta," said Ronny Poluan, 59, an Indonesian documentary maker who created the nonprofit organization in 2008.
Recent years have seen "poverty tourism" mushroom globally, from the favelas of Brazil to the slums of Dharavi in Mumbai, popularized by the film "Slumdog Millionaire."
"We have about 10 tours per month, with two to four tourists each time. More and more people are coming, some now even come just for my tour," Poluan said.
"I've had tourists from as far away as Washington. They're not only backpackers, but also businessmen, bankers," he added before being cut short by shouting reverberating around the slum.
"Kereta! Kereta!" ("A train, a train") cried mothers rushing to grab children playing on the track as a roaring locomotive approached, whipping up clouds of dust and garbage as it surged towards the flimsy-looking shacks.
The train recently claimed the life of one little girl who died as she ran after her cat.
The slum dwellers, like half of Indonesia, live on less than two dollars per day. Each tourist pays 500,000 rupiah ($54) to visit, with half of that going to the tour company, and the rest funding doctor visits, microfinance projects or community projects such as school building.
"I don't give cash. I pay the doctors directly for example," said Poluan.
But that does not reassure some critics.
"I'm against slums being turned into tourist spots," Wardah Hafidz, an activist with the Urban Poor Consortium, told AFP. "It's not about shame. People should not be exhibited like monkeys in the zoo.
"What residents get from these tours, in cash or whatever form, only strips them of their dignity and self respect, turning them into mere beggars.
"They not only become dependent on handouts, but come to expect them. It doesn't help them to believe they are capable of standing on their own two feet or getting them out of the spiral of poverty," she added.
Nonetheless, residents say they look forward to the daily influx of foreigners witnessing their lifestyles.
"I like that foreigners want to know about us. It's good they want to know about us," said Djoko, a father in his fifties, as he removed labels from a pile of glass and plastic bottles before selling them for recycling.
Tourists deny voyeurism, instead saying that what they witness inspires them to action.
"If I had not seen it, I would not have done anything about it," said Caroline Bourget.
A teacher at Jakarta's French school, she is now discussing setting up a mobile school in the slum to give disadvantaged children a better chance in life.
"Here we are at the heart of reality," she said.