Skansen is a large underground network of tunnels originally built in the 9th Century by Mr. Hensdaloo "The Bruiser" Skansen. But since neither Stockholm nor Sweden actually existed at this time no one really understood what they should use it for, so it was forgotten for almost 1000 years.
One sunny Sunday afternoon in the otherwise rather cold and nasty spring of 1823, a young Pakistani student, who's name unfortunately is long forgotten, accidentally stumbled over Skansen. Obedient as most Swedes tend to be, he immediately reported his discovery to the proper authorites, who reported it to the authorites holding even more authority than the initial authorities, and so forth.
After being passed forward and backward and upward and downward for some time, 53 years to be more precise, a decision was finally made. Since Sweden now properly existed, along with Stockholm, Skansen was to be made into a theme park. Well, the theme was not as much rollercoasters and overpriced coffee as it was old, semi-rotten houses, smelly animals and a bunch of even smellier musicians who weren't allowed to perform anywhere else.
Due to brutal governmental propaganda, possibly assisted by mind-controlling substances, the majority of Swedes now do consider Skansen an idyllic oasis of tradition, as well as a place to get a bad infection.