What is the modern-day location of the ancient city of Byzantium?

The ancient city of Byzantium is located in what is currently known as Istanbul, Turkey. When it was transformed into Constantinople in 330 AD, it became the capital of the Eastern Roman Empire. Over time, this city not only retained its historical significance but also evolved into a major cultural and political center. The term "Constantinople" specifically refers to the city after its renaming in honor of Emperor Constantine the Great, who played a crucial role in its development.

While Greece has historical ties to Byzantium and would refer to the broader geographical area, it is not the accurate answer regarding the specific city associated with the later name of Constantinople. Other options such as Egypt and Rome also have major historical significance but are not related to the location of Byzantium. Thus, selecting Constantinople accurately reflects the modern understanding of Byzantium's historical evolution.