Flensburg Firth or
Flensborg Fjord (; ), is the westernmost
inlet of the
Baltic Sea. It forms part of the border between
Germany to the south and
Denmark to the north. Its length is either 40 or 50 km, depending to the definition of its limits. It has the largest surface of all
Förden and East Jutland Fjorde, which are a special type of inlets, different from geological
fjords.