Represa do Rio Paraibuna is one of the crown jewels of the Paraibuna region in São Paulo state, a vast and remarkably pristine reservoir holding approximately 5 billion cubic meters of water across a shoreline and island-studded expanse of 760 kilometers. Formed by the impoundment of the Rio Paraitinga and Rio Paraibuna, the reservoir was constructed in the 1970s and serves the dual purpose of regulating the flow of the Rio Paraíba do Sul and generating hydroelectric power. What sets this reservoir apart from many others in Brazil is its exceptional water quality — classified as Type 1, meaning it carries no detectable pollutants. This distinction was recognized at the ECO 92 referendum, where Represa do Rio Paraibuna was honored as the most ecologically well-preserved reservoir in Brazil. Scattered across its waters are 204 catalogued islands, many of which shelter preserved Atlantic Forest flora and fauna, creating a rich and diverse aquatic ecosystem that supports healthy fish populations and makes this one of the most scenic and rewarding sport fishing destinations in the state of São Paulo.