Complex sentence: Bieszczady is the western part of the Eastern Beskids (Beskidy Wschodnie) mountains between Łupkowska pass (640 m) and Wyszkowska pass (933 m).
Split into simpler sentences: Bieszczady is the Polish name of the western part of what the Poles call Eastern Beskids (Beskidy Wschodnie). The mountain range is situated between the Łupkow Pass (640 m) and the Wyszkow Pass (933 m).