"According to author George R.R. Martin, Dorne is loosely inspired by Spain, particularly the south's Moorish heritage, which culturally sets it apart from the rest of the country and of Western Europe."
Dorne
Can't find a direct quote though.
That was obvious.
Westeros is all based on Europe during the Middle Ages.
Plus, the Dothraki are based on wild, nomadic Arab tribes.
The Summer Isles is still mostly unexplored (by Europeans) Africa.