This is a gigantic floating shantytown of homes built atop rafts of balsa wood that rise and fall with the river.
It is an exotic sight, with children jumping into the water from their front porches and entire families paddling along the waterways in dugout canoes. Closer to the riverbank, other families live in thatched homes lifted above the water on rickety stilts.
Because of the recent meandering of the Amazon away from Iquitos [1], the whole area becomes a gigantic mudflat during the dry months of July–December. Although the municipality does a good job with trash collecting, there are serious health problems during the dry months because of the open sewers.
To visit the floating city, head down Próspero south from the Plaza de Armas to Belén’s raucous and colorful market, which begins around García Sanz. Along with plastic kitchen items and cheap clothing imported from Brazil, vendors sell every imaginable jungle fruit and vegetable, dried fish, medicinal herbs, chickens, and contraband meat of sajino (wild pig) and venado (deer). If you are tall, you will be ducking frequently under the plastic awnings. The smells of garbage, mud, and all of these foods baking in the sun can become overpowering at times, so visit in the morning when the market is cleanest and most active.
Once in the market, head left toward the waterfront along 9 de Diciembre and walk out on wooden walkways toward the water. Here, people with canoes will paddle you around Belén for US$3 a half hour. Make sure to bring sunscreen, glasses, and a hat because the sun on the river is poweful. The area is relatively safe but locals will insist that you should not go on your own. It is best to leave valuables and most of your money behind. Ask at your hotel about the latest updates on security in the Belén area.
Links:
[1] http://www.moon.com/destinations/peru/the-amazon/iquitos