This is the 6135th most frequent Japanese word.
オーストリア
Austria.
In this sentence, 'オーストリア' refers to the country Austria, and it is used as the subject of the sentence to highlight its characteristic of having beautiful nature.
オーストリアは美しい自然で有名です。
Austria is famous for its beautiful nature.
In this sentence, 'オーストリア' again denotes the country Austria, and it helps to provide location information for Vienna, the capital.
私はオーストリアの首都ウィーンを訪れたいと思っています。
I would like to visit Vienna, the capital of Austria.
Here, 'オーストリア' modifies '音楽' (music) to indicate that the type of music being referred to is Austrian music.