Batumi Fortress, nowadays referred to as Tamar’s Fortress after the name of the Georgian queen Tamar (1184-1213), lies where the River Korolistskali flows into the Black Sea. The word Batumi derives from the ancient Greek name of the place and the river – Bathys, while the harbor in its estuary was called Bathys Limen (Latin Portus Altus), meaning “Deep Harbor”. Erected on a high, natural hill on the coast, the fortress controlled the sea traffic between the settlements located on the Black Sea east coast. Batumi Fortress is part of the chain of fortifications built in west Georgia in late Roman-early Byzantine epoch and played an important role during Byzantine- Persian war for gaining domination over the region. It is identified with Losorium fortress constructed by Emperor Justinian in Lazica.
It has been confirmed that the hill which preserves the ruins of the fortress was the oldest settlement discovered on the territory of Batumi. Archaeological artifacts of late Bronze-early Iron, Classical, Hellenistic, late Roman-Byzantine periods and of the Middle Ages reflect a long history and importance of Batumi. Most of the artifacts are kept in the Batumi Archaeological Museum.