Located in the Karakas Desert north of Moravia, it was one of the two forts that fortified the border with the City-State of Jowston. During the Gate Rune War, it was under the jurisdiction of Kasim Hazil, and soldiers were always stationed there to defend against Jowston incursions. As such, it was always on alert and ready to deploy.
As part of the Toran Liberation Army strategy to take Senan and rescue Viktor and Warren from Moravia, Lepant was ordered to attack the Fortress of Duha with the intention of drawing out reinforcements from Moravia to give time for the castle to be infiltrated by the Liberation Army officers. Lepant's forces would fall back and as the Imperial reinforcements fell back to Moravia, they would be ambushed by the Jowston army.
- The Fortress of Duha is never seen and does not have any sprite or indicator on the world map.
- Genso Suikoden Encyclopaedia (ISBN 4-575-16297-3), page 189