Gotland is Sweden's largest island. Once home to Vikings, Hanseatic merchants, pirates, and knights it is now a popular Swedish vacation area. Visby's Old Town with its ring wall and moat, is like something out of a fairy tale.
For more on things to see and do in Gotland see Notable Travels: http://notabletravels.com/destinations/europe/Sweden_Gotland/Gotland.html