One of my goals was to see at least one great river on each continent. I had seen the Mississippi several times, so the next closest was the Amazon. The Amazon basin is vast, with two rivers joining at Manaus, Brazil to form the combined Amazon River that empties one third of the earth’s fresh water into the Atlantic Ocean. Manaus is roughly one thousand miles from the coast. We flew into Mansus and took a river boat upstream along the Rio Negro to the Ariau Towers. You can find their site at http://www.ariauamazontowers.com/. If you visit the site you will see that we weren’t really roughing it, nevertheless, it was an amazing adventure. We had a room in a tower located about 3/4 mile away from the main complex, where the food, medical and small store was located. To reach the room we walked our luggage along an elevated wooden board walk, that had two levels: one for the dry season and one for the wet. We were on the upper level so part of the time there was water below us. The room was spacious with a queen bed and a twin bed and private toilet and shower. There was another room below us but we never saw the occupants. A screened porch gave a rocking chair view forty some odd feet above the jungle floor.
We met our guide Jorge back at the main building along the dock where he directed us and about 8 others into an open boat with a outboard on the back. We headed out onto a river so wide you could barely make out the other side. Half an hour later, Jorge eased the boat into an open area among some tree tops and we picked up our poles, literally ten foot long tree tops that had a t of monofilament attached, a steel leader at the end of the mono-filament and a hook at the end of the leader. Jorge had a supply of bloody beef cubes about the size of the end of your little finger with which we baited the hooks. Jorge watched with amusement as we dropped the hooks into the water and nothing happened. ” You have to make some noise. Splash the water with the ends of your poles.” Then he said to pull up the poles. All the bait was gone. He said that there were so many of the fish and their teeth so shaarp that you had to be very sensitive to feel them bite and then set the hook. We re-baited and Jorge pulled in a Piranha. I pulled in the next one.
The fish were not very big, but the teeth looked as big as the teeth on a carpenter’s saw. Jorge and I caught a couple more and it was time to go. 
Jorge said we could swim in the river downstream if we liked, but, not to get into the water if you had an open wound or scrape because the blood would attract the fish. We ate the fish for dinner and defered the swim until the next day.