You can walk into Stockholm but after we took our walking tour we got on a bus to take us to the Nordic Hotel to go to the Ice Bar, but you can certainly walk around the area lots of little shops etc. You also can walk to the nice area of Tallin (beautiful)fairy tale looking city. When you dock in Poland you are in Gdanyia and its a shipyard and I believe its a little ways (miles) to Gdansk I wouldn't work we toured the city of Gdansk and went to Stutthoff Concentration Camp (very moving). Oslo the ship docks next to a beautiful castle and you can walk around and last Helsinki if I remember was close to town but a bit of a walk. I have not had the pleasure of going to Spain or Portugal and I've been to Paris not by ship. Lucky you a 27 day cruise I wished I was going!! You will have a wonderful time. Hope this help,
You know Pat, when the ship had the tours out on the web a few months prior to sailing we printed them all off for each stop and study them before we picked, that was hard so many places to see but heck that is half the fun and how often are you in some of these places !