Historical clue formulations

• Iberian wine city — 2022-07-19
• City on the Douro River — 2018-10-27
• City north of Lisbon — 2018-01-05
• Iberian wine city — 2013-09-22
• Iberian city that lends its name to a variety of wine — 2010-11-05
• Wine city north of Lisbon — 2010-05-23
• City north of Lisbon — 2000-06-22
• Portuguese city — 1998-03-01
• Portuguese city — 1996-02-07
• City north of Lisbon — 1995-11-24
• City north of Lisbon — 1994-01-02