Battleship Island
Gunkanjima
proper noun
A 軍艦 is a battleship, and 島 is an island. Welcome to... Battleship Island (go Jurassic Park music).
ぐんかんじま
This word uses the on'yomi readings for 軍 and 艦, and the kun'yomi reading for 島. You learned all of them, so you should know the reading already! Oh, but watch out for the rendaku.
アイツはぜんぜん面白くないな。話題といったら軍艦島の都市伝説だけだし。
He isn’t interesting at all. All he talks about is the urban legend of Battleship Island.