From a DesignBoom.com online article:

the long and colourful history of haapsalu episcopal castle began when it was built in the 13th century, but since the 17th century the main castle has been in ruins. kaos architects‘ conservation and renovation has resulted in a journey along the walls and within the castle. the renovated castle invites guests to admire the castle’s structure closer and view the picturesque town of haapsalu from an unusually high vantage point. the guests now experience the medieval environment from another level.