Alternatively, travelers can visit a South African township in a bike or a Volkswagen Combi—the sort of vehicle typically used there and move at eye-level with people in the community, visiting restaurants and spending money on handicrafts. "One is voyeurism and one is seeking to understand how people live differently in the contemporary world," explains Goodwin. "That's much more of an exchange."

Travelers should also look for tour operators who are deeply involved in the community. Way, of Reality Tours, plans to donate 80 percent of his profit—once he makes one—to local aid groups. In the meantime, he's already built a community center in Dharavi. "People will rightly be skeptical, but we try to be as transparent as possible." He says he limits his tours to six people and has a strict no-camera policy. "The reaction from the people in the area is either indifferent or they are genuinely happy to see the tourists." In some cases, it's the traveler who ends up giving back to the community. After Micato Safaris' clients visit Nairobi's Mukuru slum in Kenya, many are moved to sponsor a local child's education; one was so inspired by his visit that he raised enough money to build a community center there.

Why the urge to nose our way into the lives of the poor? Armstrong thinks it's only natural to crave a better understanding of your surroundings. His idea for the favela tours was hatched when he worked for a hotel in Senegal and was curious to learn more about the country himself. "I was disturbed by so many guests going to the hotel only to relax on the beach or play golf, without any interest to actually know a bit of Africa." David Marek, founder of Ker & Downey, says his company offers a tour of Cape Town's District Six resettlement area as an option in one of its South Africa itineraries because it's a part of the country's heritage. "It may be a dark spot, but South Africa is full of those so you can't overlook them."

There's another point. "The economically poor are not necessarily culturally poor, and that's one reason people are interested in them," says Goodwin. "Many have rich traditions of music and dance and strong social structures." Out of the favelas, for instance, emerges a new sound that fuses hip hop and traditional Brazilian music.

It's also a chance for interaction with locals, something more travelers prize above passive sightseeing. In fact, many safari clients who stop in Mukuru say it was the highlight of their trip. "I hear that time and again," says Micato's AmericaShare founder Lorna MacLeod, "It all comes down to the human connection."