The fortress of Tureta on the Konati Islands, located on the northern stretches of Dalmatia, south of Zadar and west of Sibenik in Croatia, dates back to late Antiquity. It is arguably the finest Byzantine edifice still standing in and around the network of islands associated with Konati.
Many theories have been brought forward to explain its function. The most obvious is that it likely first served as a military outpost, guarding and controlling the waters along the Adriatic sea from the middle of the sixth century onwards. With much of the sea traffic around the Adriatic possibly insecure, it is said that Emperor Justinian (after his Gothic wars) built a dozen or more similar fortress along the Adriatic. They also served as observation posts, towers and fortifications, securing and improve seafaring conditions and protecting Byzantine settlements on and off the coast of Dalmatia.
Of interest, a list of some notable Byzantine fortifications in the chain of islands in Croatia include the ruins of the Almis on the small islet of Sveti Marko (St. Mark), St. Damjan on Rab, the Byzantine fortification in the old town of Krk and the fortification on the islet of Palacol, which safeguarded the entrance of Osor.