Arroyo Piray Guazú is a tributary of the mighty río Paraná located in the province of Misiones, Argentina. Its name, drawn from the Guaraní language, translates poetically to "river of the fish" — a fitting designation for a waterway that winds through one of South America's most biodiverse freshwater regions. The arroyo originates at Cerro Alegría in the northern sector of the Sierra de Misiones and flows until it empties into the Paraná approximately two kilometers upstream from the town of Puerto Piray, in the Departamento Montecarlo. The stream passes beneath the Ruta Nacional N° 12 via a distinctive curved bridge — locally known as the "puente banana" for its banana-like shape — constructed in early 1969, which connects the departments of Montecarlo and Eldorado. Along its banks sits the municipal balneario (recreational waterfront) of the city of Eldorado, a popular destination during the summer months.