Bird box query

Hi, can anyone advise me as to whether birds only use bird boxes that are on a wall/fence etc? I've just been given a very pretty bird box from Austria and was thinking about making it free-standing by attaching it to a tall wooden pole (like a bird table pole) and securely putting it amongst my shrubs, but I am wondering, with it being put in more of an open area, if birds would use it to nest in or not.