A very good holiday. Got the impression that, compared to the Russian and Danube cruises which we have also taken with Viking, this Duoro cruise struggled a little to find really interesting places to take us off the ship. Best were Salamanca and Lamego, but Favaios and Castelo Rodrigo were hardly riveting. Also too much concentration on visits to (usually port) wineries where nothing was happening and therefore little to see. Vessel excellent, with first class accommodation and food, as usual. High marks also for the staff, escorts etc. A suggestion - what about organising holidays with 4 days on the ship (ie travelling either up or down stream), You could start in Madrid (2-3 nights), then visit Salamanca (1 night) en route for the ship at Barca D'Alva then sail to Porto (4 nights on board) with visits to eg Lamego, Mateus, etc and Porto, and then Coimbra (1 night) and Lisbon (3 nights) (or in opposite direction). That would make an excellent 11-12 night holiday, and extensions could be offered as now at either end.