Possible Clues:

• Iberian wine center with a wine center?
• Inferior head travelling south, as far as European location
• City north of Lisbon, as it's sometimes known
• One Iberian city after which a dessert wine is named
• Poor to riot in Portuguese city
• Portuguese city near the mouth of the Douro River
• Content to shop or tour city
• Portugal's second most populous city, to some
• Troop review round Iberian city
• Portugal's second city