The Heart of Davy Jones is Heart that Davy Jones tore out of his body and put it in a chest. He locked the chest a buried it on an island. The Heart is in Lego as well it appears in The Mill set. Many times Hadres has tried to get his hands on the Heart but it ended up in James Norrington's possesion. He gave it to Cutler Backett and Cutler made Jones be part of his fleet otherwise he would stab the heart but in the end it was Will Turner who stabbed the heart and became captain of the Flying Dutchman. Will Turner had to then put his heart in a chest and left it with Elizabeth Swann so that she could keep it safe.