Nick, I just id that it and it appears to have listed under the "Desktop" a 99GB folder called 'Archive' which has a 35GB photo folder I thought I had deleted or moved and other deleted folders. Should I be keeping this "Achieve'?
You probably didn't delete the folder. Your copy of iPhoto has its own trash that must be emptied before photos placed in it will be deleted from the hard drive. Make sure you don't need the archive folder and then go into iPhoto and delete it from the iPhoto trash.