Angel Island (formerly called and also known as the Floating Island) is an island floating high in the air. It was first introduced in the video game Sonic the Hedgehog 3. The island is the home of the Master Emerald, which keeps the island suspended in the sky. The emerald is protected by Knuckles the Echidna, an inhabitant of the Island, and only surviving member of an old society that once inhabited the island. In some continuities, there is a selection of Chaos Emeralds on the island itself.