Located on The Mediterranean Sea on the western side of The Nile Delta, Alexandria was built to serve as the major Egyptian seaport. Its great lighthouse, which was equivalent in height to a 40 story building, reportedly could seen for about 35 miles / 57 kilometers out to sea, and was counted among the so-called "seven wonders" of the world.
Alexandria was a great center of ancient knowledge and learning. The famous Alexandrian Library had perhaps 700,000 volumes, which were lost after the city was burned by Arab forces in 642 AD.
Alexandria is not mentioned in the Old Testament, since it did not exist during that time. It did however become the home of many thousands of Jews, and later, Christians. The city does receive mention in the New Testament:
"Now a Jew named Apollos, a native of Alexandria, came to Ephesus. He was an eloquent man, well versed in the Scriptures. He had been instructed in the way of the Lord; and being fervent in Spirit, he spoke and taught accurately the things concerning Jesus." (Acts 18:24-25 RSV)
"There the centurion found a ship of Alexandria sailing for Italy, and put us on board." (Acts 27:6 RSV) (see Paul's Journey To Rome)
Fact Finder: What famous ancient Greek translation of the Hebrew Old Testament was produced in Alexandria?
See The Septuagint