The capital of Peru’s Maynas Province is the world’s largest city (population approximately 422,000) not accessible by car. While Iquitos’ growth was spurred by demand for Amazonian rubber in the 19th century, many visitors today are tourists who arrive by plane with plans to cruise the Amazon River and its tributaries. Most such cruises, some of them five-star luxurious, begin and end here, offering a glimpse of a city that while aesthetically crumbling remains a colorful, charming, and relatively prosperous jungle outpost.