Take a visit to Swedens forth biggest city uppsala, only 40min with train from Stockholm. On a small area you can se all the must see and highlights together with a knowledgeable authorized Uppsala city guide, the cathedral X the castle, the botanical garden of Uppsala, the university main building, the university library, some viking age runestones etc. Only run if at least two travelers book.
For a full refund, cancel at least 24 hours before the scheduled departure time.