Cenchrea was Corinth’s port that was located about 6.5mi. [9 km.] east on the Saronic Gulf. It was Corinth’s life-line to Athens, to Asia Minor, and to additional ports in the eastern Mediterranean.
Having stayed at Corinth for 18 months, Paul set sail for Jerusalem (via Ephesus and Caesarea) from here at the end of his second missionary journey (Acts 18:18). Just prior to his departure he cut his hair in Cenchrea—in fulfillment of a vow (18:18)
Later, writing to the church at Rome while staying at Corinth on his third journey, Paul commends Phoebe, a deaconess of the church at Cenchrea to the church at Rome (Romans 16:1-2).
A picture looking north at the north mole that stretches from left (land) to right, out into the sea. The port area is between where this picture was taken and the mole. It has subsided because of earthquakes. On the seaside point of the mole are the remains of a Roman Tower.

Due to seismic activity, the harbor of Cenchreae has sunk about 7.5 ft [2.3 m.] from the New Testament era. In Paul’s day this basilica shaped structure may have been a temple for the deity Isis. Later it may have been turned into a church dedicated to Phoebe.