Question: What is the area of this region of Central Europe located mostly in Poland, in which Złotniki Lubańskie was formerly part of the historic Upper Lusatia region at its border?
Sentence (from "Złotniki Lubańskie"): Złotniki Lubańskie (German: "Goldentraum" ) is a village in the administrative district of Gmina Leśna, within Lubań County, Lower Silesian Voivodeship, in south-western Poland.
Relevant evidence: Yes