This study examines the evolution and lasting impact of a section of the Habsburg-Ottoman borderlands which was established in 1664 along the Raab river and existed until the 1680s. Although it was short, the upcoming events that led to this period and the contrasting fates of the two sides of the river during the era were to leave a profound mark on the cultural memory of local communities as well as those living in the hinterlands. It will be shown in the article how the river delineated and imprinted the sense of West and East in both popular consciousness and historiography. In particular, the study will contextualise two castles (Hainfeld and Bertholdstein) on the Styrian, i.e., western, part of the area, pointing out the continuity of their development between the Ottoman through the Post-Ottoman periods. Among the Post-Ottoman personages who ensured the Islamicate continuity of these two castles, Joseph von Hammer-Purgstall and Władysław Kościelski will be highlighted in the essay.