Südtondern is an Amt ("collective municipality") in the district of Nordfriesland, in Schleswig-Holstein, Germany.HistoryIts seat is in Niebüll. It was formed on 1 January 2008 from the former Ämter Bökingharde, Karrharde, Süderlügum and Wiedingharde, and the municipalities Niebüll and Leck.In addition to the main seat in Niebüll, there are offices in Leck, Risum-Lindholm and Süderlügum.