Alexandria is the second biggest city and main port of Egypt. It was founded by Alexander the Great and is home to numerous interesting historic sights. Since Egypt has so many sights and most of the are south of Cairo, some people tend to skip Alex - bad idea.
Alexandria peaked a little later than other Egyptian cities; it was ’only’ founded some 300 years BC, making it a vey young city by Egyptian standards. But soon the city flourished like no other city. Under the Ptolomies it was probably the most important center of (Greek) culture in the world. When after the death of Cleopatra the city fell to the Romans it continued to be important, but its glory faded slowly. When the Arabs came in the Library had already been burnt down twice (so it wasn’t the Arabs!).
Having read this short resume, it will not come as a surprise that Alexandria has a lot of historic Alexandria,sights:sights, but fortunately this is not all: Alexandrai is a very lively city. It is a major summer resort for Egyptians (as well as other people from the Middle East) and there is always something going on. With a climate that is a lot better than that of Cairo (less polution e.g.) and good beaches nearby, Alexandria is a must-visit.
