From Sonic Retro
Christmas Island is the birthplace of Sonic the Hedgehog. It was established in an interview with "Sonic", published in the November 1990 edition of Sega Players Enjoy Club. In the interview, Sonic describes Christmas Island as his place of birth, a strange world where he and his friends live.
Sega's internal story documents, circa the mid-1990s, also refer to Christmas Island as Sonic's place of birth. Rather than living there, it's said that his love for adventure called him away and he has visited so many different places on Earth that he doesn't really have a place he considers to be home.
According to Yuji Naka, Christmas Island is where the action in Sonic's universe first unfolded and is populated only by animals and robots. Naka also revealed that Christmas Island is based upon the real world location (also known as Kiritimati), where nuclear weapon testing was conducted by the United States.
|Locations in the Sonic the Hedgehog Game Series|
|Islands||Christmas Island | South Island | West Side Island | Angel Island | Cocoa Island | Flicky Island | Prison Island | Onyx Island | Southern Island|
|Landmarks||Never Lake | Mount Mobius | Emerald Shrine | Tails' Workshop | Babylon Garden | Gaia Gate|
|Regions / Nations||Eggman Empire | Station Square | Mystic Ruins | United Federation | Central City | Soleanna | Monopole | City | Mystic Jungle|
|Vessels||Death Egg | Death Egg II | Egg Carrier | Space Colony ARK | Eggman Fleet|
|Planets / Planetoids||Mobius | Little Planet | Black Comet | Interstellar Amusement Park | Lost Hex|
|Dimensions||Special Stage | Maginaryworld | Sol Dimension | Arabian Nights | Twilight Cage | Grand Kingdom | White Space|