How to spend a month in Northern Europe?

"What cities or towns in these countries have beautiful scenery and old building?" Umm... all of them that you mentioned. Well, you didn't mention Oslo, which is one of the cleanest capital cities I have ever visited. No canals, but there's plenty of water. Worth about 2-3 days of your time. St. Petersburg, of course, needs no introduction. 5 days would be ideal, but 3 are probably adequate. I'm headed to Finland in two days, I'll report back after my trip. I felt I had a good overview of Copenhagen in a weekend, although I could have used more time. I've wanted to explore more of Jutland and Bornholm, but haven't made it up there yet. Headed to Sweden in November, although I'm not spending time in Stockholm. Trip report to follow. Krakow you can see in a day. Add an extra day each if you want to visit the salt mines or Auschwitz. Depending on how you decide to string the trip together, you may want to add some stops between St. Petersburg and Krakow, unless you fly between them. By train, it takes about 3 days to travel between the two. Consider one or more of the Baltic capitals ( I really liked Vilnius) and definately Warsaw.

Hi, Keep in mind that between Sweden, ie., close to Stockholm, and Poland are ferry connections, which can be used to get to Gdansk (Danzig)...you didn't list this but I highly recommend it... and then by train to Torun (Thorn). As for old buidings in cities, see in Gdansk the old town (Danzig's Altstadt). Some of them go back to the Middle Ages. That former West Prussian lower Vistula area is very scenic. In 2005 I was in Poland again, this time in Torun, one of the spots on your itinerary. I would suggest taking a day trip r/t to Chelmo (Kulm in Kulmerland), ca. one hour by bus, one of the small towns that escaped the war, very revealing.

@Ralph... St. Pete..midnight sun
Crazy? As in good crazy, or bad crazy?

In a month - I will bet you could see all that you have listed. And it sounds AWESOME! I have only been to Denmark, but I am huge and opinionated fan. In Copenhagen, I think hanging out in Nyhavn is a must - as is Tivoli. I JUST LOVE TIVOLI. So cute - so fun - so much yummy food. The Amalienborg Palace is lovely, and is actually in use as the winter home of the royal family. Christiansborg Palace has a fairytale look to it - it's gorgeous. My favorite is Kronburg Castle, in Helsingør, which is a couple of hours north of the city. It's the castle in "Hamlet!" Back to Copenhagen. IMHO, you can skip the little mermaid in the harbor if you aren't out that way for something else, although she is charming. Whatever you do, don't skip strolling down the Stroget - great shops, superb people-watching, lots of fun. I also love Christiana, which is great for a stroll and maybe a picnic. My favorite beer is Carlsberg - and you can tour the brewery for free! If you are museum buffs, I believe Wednesday all the major museums in Copenhagen are free. My particular favorites are the design museum and the naval history museum - but I am a ship geek. Other towns that I adore include Roskilde (the coolest cathedral anywhere, IMHO, because the decor is so Goth), Aarhus (ultra awesome old town - amazingly well-preserved and fantastic), Odense (another fantastic cathedral, plus Hans Christian Andersen's house, which is lovely - and Funen Village, another open air museum of considerable rustic charm) and Billund (see the real, original Legoland! - seriously, it has some mind-blowing stuff, and is a hoot). If you love the open air museum thing, note that Den Gamle By (in Aarhus) has about 3 times as many buildings as Funen Village. Both are well worth it, though. And you might want to check out the incredible Oresund Bridge to Sweden. An engineering marvel!