A city in the Roman province of Asia, located in the Lycus valley near Colossae and Laodicea. The name means 'Holy City,' likely referencing its famous pagan shrine and hot springs, which made it a pilgrimage center. Paul mentions it in Colossians 4:13 as a place where Epaphras labored for the believers. Early Christian tradition associates the apostle Philip with Hierapolis. The three cities—Colossae, Laodicea, and Hierapolis—formed a triangle of communities addressed directly or indirectly in Paul's correspondence, each with distinct challenges and opportunities for the gospel in a Greek-speaking, religiously diverse region.