Just beyond Manaus, the warm dark Rio Negro pours into the cool creamy Rio Solimões, but because of differences in temperature, speed and density, their waters don't mix, instead flowing side by side for several kilometers. The bi-color phenomenon occurs throughout the Amazon, but nowhere as dramatically as here. Day trips always include a stop here, and many tour operators at least pass by en route to their lodges. Never disappoints.
Getty Images/Robert Harding Worl