Bieszczady is a mountain range that runs from the extreme south-east of Poland through Ukraine and Slovakia. It forms the western part of the Eastern Beskids (Beskidy Wschodnie), and is more generally part of the Outer Eastern Carpathians. The mountain range is situated between the Łupkˇw Pass (640 m) and the Vyshkovskyi Pass (933 m).
Frequently Bieszczady refers only to the Western Bieszczady or even only to the part of the range lying within Poland.
The highest peak of Bieszczady is Mt. Pikuy (1405 m) in Ukraine. The highest peak of the Polish part is Tarnica (1346 m).
For me - it's the best part of Poland.