Antarctic Circle
Antarctica
noun
If 南極 is Antarctica, then the Antarctica Range is the area that makes up Antarctica. That's the Antarctic Circle.
なんきょくけん
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
南極圏にはペンギン以外にも動物はいるんですか？
Are there any animals other than penguins in the Antarctic Circle?