Castle Key

Castle Key  is a special key that appeared in Hang Castle in ''Sonic Heroes. ''It is simply an usual key with the ability to open doors in Hang Castle.

Description
Castle key appearance is like the usual key. It's head has in it a green sun-like item and there is an eye in the center of the green sun. Those keys are ten and they are scattered throughout Hang Castle and they are Team Chaotix's main object in Hang Castle. While Dr. Eggman did not explain exactly what doors they open, but it can be assumed that they open the door for Mystic Mansion. When the player gets the key, the key will disappear quietly until they completely disappear like the Target Switch. They are found exclusively in Chaotix's Hang Castle version.