The small Amazonian town of Nazareth is a traveller's dream. Wildlife prowls the surrounding jungles and indigenous inhabitants practise ceremonies that long predate the arrival of the Spanish conquistadores.

But it may be advisable for tourists to give the place a wide berth. Locals have declared their town off-limits to travellers, even though this stretch of the Amazon river is playing host to more visitors than ever. Their main complaint: tourists' behaviour, and that only a fraction of the money they spend trickles down to the indigenous. "What we earn here is very little. Tourists come here, they buy a few things, a few artisan goods, and they go. It is the travel agencies that make the good money," said Juvencio Pereira, an Indigenous Guard, Nazareth's unofficial volunteer police force.

The town of 800 people, a 20-minute boat ride from the tourist hub of Leticia, takes its ban seriously. At the entrance, Pereira and other guards stand armed with their traditional sticks to deter unwelcome visitors. Nazareth resident Grimaldo Ramos feels that some tourists can't distinguish between the wildlife and the Amazon's residents, snapping photos of indigenous families as if they were another animal. "Tourists come and shove a camera in our faces," he said. "Imagine if you were sitting in your home and strangers came in and started taking photos of you. You wouldn't like it."

Nazareth's actions reveal a split among the indigenous communities that live along the river about what role tourism should play in the region's development.

With the rise of eco-tourism, this part of the Amazon, which joins Colombia, Peru and Brazil, has seen a flood of travellers arriving to experience the world's most biologically diverse region. Tourists swim with the Amazon's pink dolphins, fish for piranhas, hike through the rainforests and take in the sunsets over the mighty river. According to the tourism office for the Colombian province of Amazonas, the 35,000 people who trekked to the region in 2010 represent a fivefold surge in numbers over the past eight years. But as Nazareth complains, the indigenous people have so far seen little of the benefits, mostly just the sharp end of tourism.

A common concern among indigenous leaders is that local children are adopting the outsiders' ways, with many children more comfortable in "western" dress and listening to the imported music of reggaeton and Colombia's vallenato. There are misunderstandings of two cultures interacting. What a tourist may consider polite curiosity about indigenous culture can seem to some here intrusive and even an attempt to gain sacred tribal wisdom. "We don't like it when they ask members of the community about our traditional knowledge and the medicines we possess," said Pereira.

Other communities, however, take the view that the number of visitors to the region is going to rise, so they might as well profit from it. A couple of hours downriver lies Puerto Narino, whose mayor, Nelson Ruiz, understands Nazareth's worries, but says that if tourism is well-regulated it can help lift communities out of the poverty that troubles much of this zone.

He added that visitors are expected to abide by certain rules, such as no drug-taking and no sexual tourism.