So you have the best looking avatars that you would like your members to use. The problem is that you have no idea where to place them. You are in luck, this tutorial will show you how to create your own folder and place your new avatars.
Steps :
phpBB default avatar folder is located at modules/Forums/images/avatar/gallery . You can upload your images here but you can also create your own folder instead of "gallery" with any name you choose and place your new avatars. When a user goes to choose an avatar they will see a drop list where they can choose the name of the new folder and see all the avatars available.
That was really simple, wasn't it?