From Wikipedia.org, regarding the city of Hippo: "Hippo Regius is the ancient name of the modern city of Annaba, Algeria. Under this name, it was a major city in Roman Africa, hosting several early Christian councils, and was the home of the philosopher and theologian Augustine of Hippo. In even earlier days, the city was a royal residence for Numidian kings.
"The climate is agreeable in winter, but humid in summer. The harbour serves as an export station for all of the rich inland country."
If you don't have Story of the World at your fingertips, this link—and this site—manage to put history in kid-friendly terms. (Note: If you do aim to purchase Story of the World [SOTW in our circles], I'd offer my recommendation for the audio book, which my kids have requested for bedtime tonight! It's great for them to be able to do something they enjoy while taking in their history…as many times as they would like. Jim Weiss, the reader, is a renowned storyteller.)
A picture is, of course, worth a thousand words, and here are about that many images of Augustine.