In ancient times, the city was known for the Lighthouse of Alexandria (one of the Seven Wonders of the World) and the Library of Alexandria (the largest library in the ancient world). Ongoing maritime archaeology in the harbour of Alexandria (which began in 1994) is revealing details of Alexandria during the Ptolemaic dynasty.

Persistent efforts have been made to explore the antiquities of Alexandria. Encouragement and help have been given by the local Archaeological Society, and by many individuals, notably Greeks proud of a city, which is one of the glories of their national history.

The past and present directors of the museum have been enabled from time to time to carry out systematic excavations when opportunity offered; D. G. Hogarth made tentative researches on behalf of the Egypt Exploration Fund and the Society for the Promotion of Hellenic Studies in 1895; and a German expedition worked for two years (1898–1899). But two difficulties face the would-be excavator in Alexandria.

Since the great and growing modern city stands right over the ancient one, it is almost impossible to find any considerable space in which to dig, except at enormous cost. Also, the general subsidence of the coast has sunk the lower-lying parts of the ancient town under water. This underwater section, containing much of the most interesting sections of the Hellenistic city, including the palace-quarter, is still being extensively investigated by the French underwater archaeologist Franck Goddio and his team [2] and [3]. It raised a noted head of Caesarion, left. These are even being opened up to tourists, to some controversy [4].

The spaces however, that are most open are the low grounds to northeast and southwest, where it is practically impossible to get below the Roman strata.

The most important results were those achieved by Dr. G. Botti, late director of the museum, in the neighbourhood of "Pompey's Pillar," where there is a good deal of open ground. Here substructures of a large building or group of buildings have been exposed, which are perhaps part of the Serapeum. Hard by immense catacombs and columbaria have been opened which may have been appendages of the temple. These contain one very remarkable vault with curious painted reliefs, now lighted by electricity and shown to visitors.

The objects found in these researches are in the museum, the most notable being a great basalt bull, probably once an object of cult in the Serapeum. Other catacombs and tombs have been opened in Kore es-Shugafa Hadra (Roman) and Ras et-Tin (painted).

The German excavation team found remains of a Ptolemaic colonnade and streets in the north-east of the city, but little else. Hogarth explored part of an immense brick structure under the mound of Kom ed-Dik, which may have been part of the Paneum, the Mausolea or a Roman fortress.

The making of the new foreshore led to the dredging up of remains of the Patriarchal Church; and the foundations of modern buildings are seldom laid without some objects of antiquity being discovered. The wealth underground is doubtless immense; but, despite all efforts, there is not much for antiquarians to see in Alexandria outside the museum and the neighbourhood of "Pompey's Pillar." The native tomb-robbers, well-sinkers, dredgers and the like, however, come upon valuable objects from time to time, which find their way into private collections.

Source: Wikipedia