Alexander the Great founded at least twenty cities named after himself. Ancient historians say he founded close to seventy, though many of those are suspected to have been just renamed/repopulated by Alexander. The city you are referring to is Alexandria Egypt. One of the most important shipping hubs in the Mediterranean. It was founded by Alexander in 331BC and quickly became the biggest city in the world at that time. The modern city sits on top of the site of the ancient one. List of Alexander’s Cities

This site will give you some background on mapping the ancient city of Alexandria that’s under the modern one./Ancient City Map

Also if you have Disney plus navigate to the National Geographic section and lookup the tv show, The Lost Tomb of Alexander the Great. It will give you a good visual of current archeology in the heart of the city. You’ll see what they have uncovered at the intersection of the two main roads of the ancient city.