Source of the Amazon River

As a detective, I knew that the source of the Amazon River had to be located in the Amazon Basin, and with my knowledge of geography, it became clear to me that the Amazon Basin spans across several South American countries, including Brazil, Peru, Colombia, and Ecuador. However, my intuition told me to focus on Peru because of its close proximity to the Andes mountains, which is where the Amazon River is believed to have its origins. I also knew that the Amazon River is fed by numerous smaller tributaries, many of which flow through Peru. By considering all of these factors, I arrived at the definitive answer to the crossword clue – Peru.