Santarem is a busy port for the trade flowing up and down the Amazon between the Atlantic and the inland forests. The most famous site for visitors is the “Wedding of the Waters” where the clear, dark Tapajos River meets the muddy ochre Amazon. Due to their different densities, they flow alongside each other for quite some distance, between the same banks. Local boats specialize in taking visitors to the site. Local markets are fun to explore, and other excursions include visiting the smaller tributaries and forests, and fishing for the infamous piranha fish.