Little of the ancient city has survived into the present day, Much of the royal and civic quarters sank beneath the harbour due to earthquake subsidence, and the rest has been rebuilt upon in modern times.The Pompey's Pillar is the best-known ancient monument still standing today. It is located on Alexandria's ancient acropolis , a modest hill located adjacent to the city's Arab cemetery, and was originally part of a temple colonnade. Including its pedestal, it is 30 m (99 ft) high; the shaft is of polished red granite, roughly three meters in diameter at the base, tapering to two and a half meters at the top. The structure was plundered and demolished in the 4th century when a bishop decreed that Paganism must be eradicated. "Pompey's Pillar" is a misnomer, as it has nothing to do with Pompey, having been erected in 293 for Diocletian, possibly in memory of the rebellion of Domitius Domitianus. Beneath the acropolis itself are the subterranean remains of the Serapeum, where the mysteries of the god Serapis were enacted, and whose carved wall niches are believed to have provided overflow storage space for the ancient Library.
Alexandria's catacombs, known as Kom al Sukkfa, are a short distance southwest of the pillar, consist of a multi-level labyrinth, reached via a large spiral staircase, and featuring dozens of chambers adorned with sculpted pillars, statues, and other syncretic Romano-Egyptian religious symbols, burial niches and sarcophagi, as well as a large Roman-style banquet room, where memorial meals were conducted by relatives of the deceased. The catacombs were long forgotten by the citizens until they were discovered by accident in the 1800s.