Those,but real slaves too. Owned and transfered like cattle. Mostly in Africa I believe.
Sex slaves too in Asia, but the African one more the traditional western view of it.
Even the US constitution allows it if you read it word for word.
Section 1. Neither slavery nor involuntary servitude, EXCEPT as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States, or any place subject to their jurisdiction.
Section 2. Congress shall have power to enforce this article by appropriate legislation