Mestia- Grave with Cross of Saint Nino

The Grapevine Cross (Georgian: ჯვარი ვაზისა, Jvari Vazisa) also known as the Georgian cross or Saint Nino's cross, is a major symbol of the Georgian Orthodox Church and dates from the 4th century AD, when Christianity became the official religion in the kingdom of Iberia (Kartli).
It is recognisable by the slight drooping of its horizontal arms. Traditional accounts credit Saint Nino, a Cappadocian woman who preached Christianity in Iberia (corresponding to modern eastern Georgia) early in the 4th century, with this unusual shape of cross. The legend has it that she received the grapevine cross from the Virgin Mary (or, alternatively, she created it herself on the way to Mtskheta) and secured it by entwining with her own hair. Nino came with this cross on her mission to Georgia. However, the familiar representation of the cross, with its peculiar drooping arms, did not appear until the early modern era.
(Wikipedia)