Ancient Alexandria is famous for its great library, but that’s not the only impressive thing about the city. Alexandria was the intellectual hub of the ancient world, and many great scholars lived there, either for a few years, or for their whole lives.

Here is a list of some of the most interesting people who lived and worked in Alexandria.

Euclid is one of the most famous mathematicians of all time. He basically invented geometry, and wrote the book “Elements”, which would become the main textbook for mathematics for over 2000 years.

He also wrote another famous book called “Optics” which explained light’s behavior using geometry. This theory of light was the basis of art, astronomy, and navigation for a long time.

Archimedes is another of the most famous mathematicians of all time. He invented mechanics, hydrostatics, and the concept of a center of gravity, among other things.

You might know him better as the guy who ran into the streets naked shouting “Eureka!” after discovering how to measure the weight of a gold crown. Or you may know him for the legendary quote “Give me a lever long enough and a fulcrum on which to place it, and I shall move the world.”

This name may not sound particularly familiar to you, but something that might sound familiar to you is the idea that the world revolves around the sun. Aristarchus was the first person to come up with the heliocentric model, which said that the sun was the center of the universe, and the earth revolved around it once a year.

Claudius Ptolemy was a mathematician, astronomer, and geographer. He basically invented the field of geography with his famous book “Geography”. For over a thousand years, mapmakers would rely on Ptolemy’s Geography. Christopher Columbus built on top of Ptolemy’s maps when he was making his travels.

He is also responsible for one of the only ancient books on astronomy, and one of the most influential scientific books of all time, “Almagest”. In this book, he championed the geocentric model, in which everything revolves around the earth. This became the standard of astronomy until Copernicus and Galileo over a thousand years later.

Eratosthenes was the chief librarian of the Library of Alexandria. He did great work in geography, and invented scientific chronology as well as the “Sieve of Eratosthenes” which is an efficient method for finding prime numbers.

Most interestingly of all, he was the first person to calculate the circumference of the earth, and it was surprisingly accurate (40,000 km vs 40,074 km). He was also the first to calculate the earth’s axial tilt, also to a great degree of accuracy.

Hero of Alexandria is one of the greatest inventors of antiquity. You might know him from math class with “Heron's formula” for calculating the area of a triangle given all the sides, but he did so much more than that.

He invented the first windmill and was the first to harness wind energy, which was used to operate an organ. He also invented the first vending machine.

He made a lot of cool things, but the most interesting of all was what he called an aeolipile, which is a less efficient version of what is now known as a steam engine. This was over 1500 years before the industrial revolution.