Question: What is a historically significant part of a historical region of Silesia presently located in the Czech Republic that its area is 316.9 km2?
Sentence (from "Czech Silesia"): Czech Silesia (Czech: "České Slezsko" ; Silesian: "Czeski Ślůnsk" ; German: "Tschechisch-Schlesien" ; Polish: "Śląsk Czeski" ) is the name given to the part of the historical region of Silesia presently located in the Czech Republic.
Relevant evidence: Yes