Original sentence: It is situated at an altitude of 250-400 meters above sea level and covers an area of 273 sq.Jelenia Góra valley is sorrounded by parts of the Sudetes mountains.The core of todays building emanated from the 18th century, when Maximilian Leopold von Reibnitz expanded it to a Baroque palace
Edited sentence: It is situated at an altitude of 250-400 meters above sea level and covers an area of 273 km2.Jelenia Góra valley is surrounded by parts of the Sudetes mountains.The core of today's building emanated from the 18th century, when Maximilian Leopold von Reibnitz expanded it to a Baroque palace