What city did alexander found on the nile delta and is also where the great library was located?

Alexander founded Alexandria. This was the cities name. An interesting thing about Alexander the Great, the best Macedon general to unite Greece under one banner, was that he named a lot of cities after his name - he named them Alexandria. What was the exact reason for this is hotly debated!

It is meant that like tapestry scientific theories often need to pull out since they are not relevant and often times the whole chain of theories may be pulled out.