Hierapolis
Hierapolis is a Phrygian city that surfaces once in scripture, paired with neighboring Laodicea as a place where the work of the gospel was being labored over on behalf of the Colossian believers.
A Phrygian Sister-City
Paul's closing notes to the Colossians vouch for Epaphras and his pastoral exertion across the cluster of Phrygian congregations: "For I bear him witness, that he has much labor for you⁺, and for them in Laodicea, and for them in Hierapolis" (Col 4:13). The verse sets Hierapolis on a footing with Colossae and Laodicea — three congregations carried in the heart and labor of the same minister.
The mention is brief, but the geographic linkage is precise: Christians are present in Hierapolis, and one of Paul's circle is exerting himself for them by name. The city is a Christian center in Phrygia, included in the apostolic correspondence with the wider Lycus valley.