CSA can take many forms, one of which is child prostitution. Child prostitution is the commercial sexual exploitation of children in which a child performs the services of prostitution, for financial benefit. It is estimated that each year at least one million children, mostly girls, become prostitutes.[85] Child prostitution is common in many parts of the world, especially in Southeast Asia (Thailand, Cambodia), and many adults from wealthy countries travel to these regions to engage in child sex tourism.