Balkan Mountains vs Balkans

Balkan Mountains and Balkans both are nouns.

Word	Noun	Adjective	Verb	Adverb
Balkan Mountains	Yes	No	No	No
Balkans	Yes	No	No	No

As nouns, Balkan Mountains and Balkans are synonyms defined as:

Balkan Mountains and Balkans: the major mountain range of Bulgaria and the Balkan Peninsula

Other synonyms of Balkan Mountains include Balkan Mountain Range.

Balkan Mountains (noun)	Balkans (noun)
the major mountain range of Bulgaria and the Balkan Peninsula	the Balkan countries collectively
	a large peninsula in southeastern Europe containing the Balkan Mountain Range
	the major mountain range of Bulgaria and the Balkan Peninsula