The complex included large grounds at Donja Gradina directly across the Sava river , a Sisak children 's concentration camp in Sisak , and a Stara GradiÅ ka concentration camp . The complex also included large grounds at Donja Gradina directly across the Sava River , a camp for children in Sisak to the northwest , and a women 's camp in Stara GradiÅ ka to the southeast .