I write this to help players of halo 3 to find the skulls.First was in sierra 117 wen you kill first grunds and that noob. (i dont remember his name but i call him a noob) then wen first home ship (again i dont known that machine name)come run to the right and you will find it.Secont is on the siera 117 too wen you go rescue the jonhsson. First WARNING! you must kill the hammer noob.Second cross the bridge then try go up to wall then go over the wall pass the jonhsson jail then wen you are there you dont see nothing but there is a pipe.Skull is behind the pipe.