에는 섬이

in … there is an island

→ 에
phrase Rare #31,780
in … there is an island The place before 에는 is presented as the setting or topic. The sentence ending supplies the verb, and 섬이 can refer to one or more islands.
KO: 제주도에는 섬이 많아요.
EN: There are many islands around Jeju Island.

그리스에는 섬이 많다.

There are many islands in Greece.

바다에는 섬이 있다.

There is an island in the sea.

모든 학생이 알다시피 브링오블 남쪽에는 섬이 없다.

As every student knows, there are no islands south of Bringoble.