A locking device having at least one first segment, at least one second segment situated so as to be capable of being moved relative to the first segment, at least one first segment and at least one second segment being capable of assuming at least one first and at least one second position relative to one another, and at least one segment having at least one indicator area that can be substantially permanently modified in at least one physically perceivable property, wherein a movement that is required in order to open and/or close the locking device immediately moves the position of at least one first segment relative to at least one second segment at least temporarily from the first position into the second position, and effects the modification of the physically perceivable property.