Where port wine got its name

My last stop on a whirlwind tour of northern Spain and Portugal was Porto, the city that gave Portugal (and port wine) its name. What a great looking city, with medieval churches and crumbling, pastel-coloured houses tumbling downhill to the Douro River. Walked heaps, tried some wine, drank lots of tiny, potent cups of coffee, listened to traditional fado music and ate even more cheaply than in Spain, but mostly I just soaked up this view from a bridge high above the river. 

Now I don't understand why it took me so long to visit Spain and Portugal. I won't wait another 40-odd years to go back.