Below is a list, is ascending order, of the top seven places Apostle Paul visited during his 35 year ministry.
Corinth
2 1/4 years
Paul visits Corinth twice during his ministry. His first stay (Acts 18:1 - 18), during his second missionary journey, lasted for roughly 2 1/4 years (late summer 50 to autumn 52 A.D.). This long stay was warranted as God, in a vision, revealed to him that there were many potential converts in the city.
And the Lord said to Paul in a vision in the night, "Do not be afraid; but speak, and do not be silent, for I am with you; and no one shall set upon you to mistreat you because I have many people in this city." (Acts 18:9 - 10, HBFV).
Paul visited the church a second time in early 58 A.D. during his third journey. This stay, however, was quite brief (Acts 20:1 - 3).
Caesarea
2 1/4 years
Paul, in late spring of 58 A.D., is arrested in Jerusalem on the charge that he deliberately caused a temple riot (Acts 21:26 - 22:29). Fearing the apostle would be killed by zealous Jews in Jerusalem, the Romans escort him to Caesarea so that his case can be heard by Governor Felix (23:12 - 35).
Although Paul's case in heard several times, he languishes in a Caesarea prison for about 2 1/4 years (early summer 58 to early Autumn 60 A.D.). He finally leaves the prison for Rome after he requests his case, as was his right as a Roman citizen, be heard by Roman Emperor Nero.
Rome
2 1/4 years
Paul, during his ministry, made two forced visits to Rome as a Roman prisoner.
His first time in the Roman Empire's capital took place at the end of his fourth missionary journey. Dangerous weather, along with being shipwrecked on the Mediterranean, caused him to arrive in Rome in the early spring of 61 A.D. (Acts 27 - 28).
Paul is allowed to be under house arrest in the capital from early spring 61 to early spring 63 A.D. During this time he is allowed the liberty of receiving guests and preaching the gospel to all who visit him.
And Paul remained two whole years in his own hired house, welcoming all who came to him, proclaiming the kingdom of God, and teaching the things concerning the Lord Jesus Christ with all boldness, no man forbidding him. (Acts 28:30 - 31, HBFV).
In January or February of 68 A.D. the apostle is again arrested and taken to Rome. This time, however, he will stay in prison until he is martyred in May or early June of the same year.
Arabia
3 years
Paul's preaching in Damascus, immediately after his conversion in 33 A.D., earns him death threats. After escaping the city in the middle of the night, he heads to Arabia where he is taught by Jesus Christ for three years (spring 33 to spring 36 A.D., see Acts 9:19 - 25 and Galatia 1:16 - 18).
Ephesus
3 1/4 years
The apostle makes two trips to Ephesus during his ministry. His first visit in a brief one, likely lasting only one week, during his second missionary journey (Acts 18:19 - 21). His second time in the city, however, during his third evangelistic journey, lasts from autumn 54 to early winter 57 A.D.
Tarsus
4 years
Paul, after his early preaching causes an uproar in Jerusalem, is sent by the church back home to Tarsus (Acts 9:29 - 31). He then stays in his hometown for four years (summer 36 to summer 40 A.D.). During this time he not only preaches the gospel in the city but also in the surrounding province of Cilicia. He leaves the city when Barnabas finds him and solicits his help with the greatly expanding church in Syrian Antioch (Acts 11:20 - 26).
Syrian Antioch
4 1/2 years
Syrian Antioch held a special place in Paul's ministry as it was from there that God launched his first missionary journey (Acts 13:2). The apostle will ultimately spend time in the city on three separate occasions.
His first visit was prior to his first evangelistic campaign where he spent a year helping Barnabas serve the growing number of new Christians in the city.
Then Barnabas went to Tarsus to seek Saul; And after finding him, he brought him to (Syrian) Antioch. And it came to pass that for a whole year they assembled together with the church and taught a great multitude. And in Antioch the disciples were first called Christians. (Acts 11:25 - 26, HBFV).
Paul's second visit, at the end of his first missionary journey, lasted 2 3/4 years (fall 46 to late summer 49 A.D., Acts 14:26 - 28).
Paul last stay in Syrian Antioch lasted 3/4 of a year (autumn 52 to summer 53 A.D.). It took place prior to his third missionary journey.
Conclusion
The top seven places where Apostle Paul spends the most time during his ministry (in ascending order) are Corinth, Caesarea, Rome, Arabia, Ephesus, Tarsus and Syrian Antioch. At just under 22 years total, his visits to these destinations account for roughly 63% of the time Paul spends preaching the gospel.