• The Library of Alexandria: Likely the largest center of knowledge in the world at the time, this Egyptian library is now best well known for burning down—either in 48 BC or 270 AD. Before burning, it’s estimated that the library contained over half a million scrolls.
• The Library of Ashurbanipal: Named after a 7th Century Assyrian ruler, the Library of Ashurbanipal is one of the oldest known libraries. This is where the eponymous ruler stored literature from places he conquered.
• The Imperial Library of Constantinople: Before it was Istanbul, Constantinople was the capital and intellectual hub of the Byzantine Empire. Its famous library was constructed in the 4th Century under the direction of Roman Emperor Constantine the Great.
• The Library of Pergamum: Another historic library in modern-day Turkey, the Library of Pergamum was built by the Attalid dynasty during the 3rd century. It was said to rival the contemporary Library of Alexandria, competing for knowledge and prestige.
• The House of Wisdom: In the 9th Century, the Abbasid Dynasty built the House of Wisdom in present-day Baghdad, Iraq. It housed numerous Greek, Indian, and Arabic manuscripts on mathematics, philosophy, astronomy, and science.
• The Villa of the Papyri: Smaller than the other libraries on this list, the Papyri is unique because it’s the only library whose collection remains largely intact. But only because of Mount Vesuvius’ eruption in 79 AD preserved the scrolls in a 90-foot layer of volcanic ash.