Prostitution in Mongolia is illegal but many women who enter prostitution are young women who are trafficked abroad.
One of the major destinations is China, where the victims are forced enforced endenture to repayment the people smugglers to the "fee" to get them abroad.
Mongolian women in China work as prostitutes in bars in Beijing, such as Maggie's.
References
Prostitution in Mongolia Wikipedia(Text) CC BY-SA