I want to know the answer to the following question:
What is its longest river?
All the background I'm provided with is that "The largest and most important of these rivers is the Minho, known as O Pai Miño (Father Minho), 307.5 km (191.1 mi) long and discharging 419 m3 (548 cu yd) per second, with its affluent the Sil, which has created a spectacular canyon.". Is that enough to answer the question?
Answer: yes