For those who want to see the Amazon river during their South American cruise, there is perhaps no better port than Santarem. This town is what's known as a "river port" meaning your cruise ship will actually sail up the river in order to reach the settlement.
Once you've arrived, stop for a few minutes and simply take in the massive Amazon river that the city is located on. This is one of the most amazing spots on Earth, but few people ever make the trek to visit.
Santarem is an especially amazing destination, because it is located where the Amazon meets the Tapajos, another massive Brazilian river. These two waters join close near the city, but those who go on a river cruise will notice that the waters will remain two distinct colors for several miles. Such is the force of these two rivers that it takes quite a while for the two shades to mix into one. This is known as the "Meeting of the Waters," and is truly an amazing sight. You'll be able to pick out the two rivers, as the Tapajos is emerald green while the Amazon is a muddy brown.
Back in town, pay a visit to the Joao Fona Cultural Center. This museum is housed in a 19th-century mansion and will help you learn more about the town of Santarem. This region of Brazil actually has quite a few ties to America. Many Confederate soldiers fled here after the Civil War to start life anew. Henry Ford also visited the region to establish manufacturing plants for his automobile company.
If you want to learn more about the region, take a trek through the nearby Saint Lucia Woods. This is your chance to visit an Amazonian rainforest and glimpse the various flora and fauna that is native to Brazil. But it's also an opportunity to learn about the ecological side of things and see the effects that agriculture and manufacturing is having on the region.