Ptolemais, located near the modern village of Tolmeita in Libya, was one of the five cities of the ancient Pentapolis in Cyrenaica. Founded by Ptolemy III Euergetes in the 3rd century BC, the city grew from a small Greek settlement into a significant urban center. Under Roman rule, it became the capital of Libya Superior and remained an important city until its decline in the 5th century. The ruins, including a planned city layout, amphitheaters, and a Roman aqueduct, have been well-preserved and offer insight into the city's once grand architecture and infrastructure. Additionally, Ptolemais was an early center for Christianity and the site of key ecclesiastical events.