Petra () was a fortified town on the eastern Black Sea coast, in Lazica in what is now western Georgia. In the 6th century, under the Byzantine emperor Justinian I, it served as an important Eastern Roman outpost in the Caucasus and, due to its strategic location, became a battleground of the 541–562 Lazic War between Rome and Sasanian Persia (Iran). Mainstream scholarly opinion identifies Petra with a ruined settlement of Late Antiquity at the village of Tsikhisdziri in Adjara, southwestern Georgia.