Snake Island, also known as Serpent Island or Zmiinyi Island (Ukrainian: острів Змії́ний, romanized: ostriv Zmiinyi; Romanian: Insula Șerpilor; Russian: Змеиный, romanized: Zmeinyy), is an island belonging to Ukraine located in the Black Sea, near the Danube Delta, with an important role in delimiting Ukrainian territorial waters. The island has been known since classical antiquity, and during that era hosted a Greek temple to Achilles. Today, it is administered as part of Ukraine's Odesa Oblast.