Syn City is a location within Breath of Fire III. It is the headquarters of the crime organization led by Mikba. It is well known as a hotspot for crime and the central location for many villainous gangs.
Ryu and his party are led to Syn City while tracking Rei, who is on the case of Mikba, the leader of the crime organization who attempted to kill Ryu and his friends several years ago. They arrive and discover that a "monster" has attacked the city, severely injuring and killing many people, and that Mikba has fled to the checkpoint. Nina and Garr deduce that Rei is still upset with himself for failing to protect Ryu and Teepo, so he hopes that killing Mikba will lead him to Balio & Sunder, not knowing that Ryu and co already killed them. Nina hopes to catch up to Rei before he kills Mikba, as she wants to interrogate him for the investigation. The party leaves the city, and heads to the Dauna Checkpoint to catch up with Rei and Mikba. After Mikba is killed, Syn City reopens, and although the residents say they'll stop illegal activity, it's unsure if that truly happens or not.