Translation "Be nice, respect Christiania's law, no weapons, no back labels, no bullet proof vests". Could also mean "no police" ?
This is the entrance to Christiania, a small suburb of Copenhagen, Denmark.
In 1971 hippies founded a freehaven here, where they built their own houses and refused to pay tax.
Other laws valid here : no cars inside, no hard drugs, but plenty of soft drugs.
Today it is also a big tourist attraction. More info on their own site.