Why not make a short visit to Riga, the beautiful capital of Latvia, during your visit to Sweden! It's just a boat ride away!
You'll need to make your way to Stockholm from Malmö, but you can then take an overnight cruise from Stockholm to Riga and spend the day visiting some of the most beautiful sights in Eastern Europe. Once you're done, hop back onto the same ferry for a relaxing trip back to Stockholm!
Be sure to stop in Riga's Old Town, where you can find the famous Riga Castle, founded in 1330 and less than a 15 minute walk from the ferry terminal.
An overnight cruise from Stockholm