Final answer:
The city of Alexandria housed the greatest library of the Hellenistic era, known for its extensive collection of scrolls, research facilities, and status as the ancient world's center of learning.
Step-by-step explanation:
The greatest library of the Hellenistic era could be found in the city of Alexandria. This city was not only the largest Hellenistic city, but also the location of the Museon or Museum of Alexandria, which was much more than just a place for displaying artifacts. It served as the world's largest library, with an estimated 700,000 scrolls, and was a premier center for scientific and literary studies, effectively displacing the Academy at Athens as the center of learning in the ancient world. Renowned figures such as Eratosthenes headed the royal library, contributing significantly to the fields of geography, astronomy, and literature.
During its peak, the institution embodied many characteristics of what we would now consider a research university, being directly funded by the Ptolemaic government. It attracted a multitude of scholars who conducted research based on its extensive archives and also housed lecture halls, making it the preeminent site of learning in the Hellenistic world.