High Quality Content by WIKIPEDIA articles! The Río Cañas, also known as Río Canas, is a river in the municipality of Ponce, Puerto Rico. The river originates high in the mountains of the municipality and runs in a sourthernly direction parallel to Puerto Rico route PR-123, the old road from Adjuntas to Ponce. The old Hacienda Buena Vista plantation in barrio Magueyes, now a coffee mill museum, used to use the force of Rio Cañas to turn its coffee bean grinders via an elaborate system of water channels. Continuing south and running parallel to Route 123, the river enters the city of Ponce in the area of barrio Magueyes Urbano (the urban zone of barrio Magueyes) before approaching Route 132 PR-132, the country road from Ponce to Peñuelas.