Gotland located in the Baltic Sea, right in the middle, in a strategically advantageous position for imperial domination or simple banditry and piracy.
You can get here through Sweden by ferry from Nynäshamn (this way longer and a little more expensive) or from Oskarshamn (this way closer and cheaper). There are also about Visby airport flights from Stockholm, Kalmar, Gothenburg, etc.
What about the Gotland, there is a dense network of roads on the island, and there is bus service (frequent in summer season). It will be good to have on the island your own bike, or even a personal car.