So, being sent out by the Holy Spirit, they went down to Seleucia (Acts 13:4).
Seleucia was the seaport and harbor from which Paul and Barnabas left with John Mark for their first missionary journey (ca. AD 48). It is also likely that they landed here on their way back from Attalia to Antioch (Acts 14:26), and that Barnabas and John Mark left from here when parting company from Paul and heading for Cyprus (Acts 15:39).