In the ancient world, there were many cities. During Anthony's day, we can say that world was an urban one. A visit to modern day Turkey will show this point very clearly (Ephesus, Pergamum, Alexandria to name a few). Here are few points to consider when talking about cities.
1. Some cities were very large. Rome probably had about 1,000,000 people. Alexandria probably had about 500,000, and Ephesus probably had about 200,000. These are all guesses, of course, but I add these numbers to show you that these cities were huge. To get a better idea of the scale, consider the fact that it took almost 2000 years to get to a million people after the day of Anthony (London – 1800s)!
2. Many of these cities were diverse, partially due to Roman conquest and slave trade. Martial, the Roman poet, pokes fun at many outsiders.
3. Rome was a place of politics. If there was an important decision going to be made, Rome was involved.
4. Rome and many other cities were extremely rich. Luxury goods made their ways to these cities. Roman satirists as well as Christian apologist would criticize the incredible wealth.
In the light of these points, Rome was a modern day - New York + Washington D.C.