"this area of the country is beautiful" was marked wrong, am I missing something here? Region, area and part in this context are all the same in English
"area" is a very vague word. It can denote a 5x5 cm square, it can denote whole Russia. The best translation would be "obszar".
My "correction" says This country region is beautiful. Not good English!!
In American English one could correctly say," This area of the country is beautiful."