I may be going to Finland next month. Any places I HAVE to see? Any advice?

Hello seeker, my wife and I visited the Baltic several years ago and remember it as one of our best trips. We saw most of the Baltic cities including Helsinki and St. Petersburg. If you go to St. Petersburg, you have to see Catherine's palace and the "Hermitage Museum" where the opulence of the displays is just jaw dropping. Each display room has an elderly Russian lady as an attendant. None of them ever smile and they only know two words in English, which are: "don't touch". One of the other cities we visited was "Tallin, Estonia" and we fell in love with it. Being an east European country it is relatively inexpensive when compared to westen Europe and the people are so freindly. It seems not to have changed much over the last 100 years (ex-soviet). We went to the old town part where they still have cobblestone streets, street peddlers and the old architechture. A very nice place !