City and London. This temple became, in time, the Patriarchal Church, though some ancient remains of the temple have been discovered. The actual Caesareum, the parts not eroded by the waves, lies under the houses lining the new seawall. The Gymnasium and the Palaestra are both inland, near the Boulevard de Rosette in the eastern half of the town; sites unknown. The Temple of Saturn; site unknown. The Mausolea of Alexander (Soma) and the Ptolemies in one ring-fence, near the point of intersection of the two main streets. The Musaeum with its famous Library and theater in the same region; site unknown. The Serapeum of Alexandria, the most famous of all Alexandrian temples. Strabo tells that this stood in the west of the city; and recent discoveries go far as to place it near "Pompey's Pillar," which was an independent monument erected to commemorate Diocletian's siege of the city. The names of a few other public buildings on the mainland are known, but there is little information as to their actual position. None, however, are as famous as the building that stood on the eastern point of Pharos island. There, The Great Lighthouse, one of the Seven Wonders of the World, reputed to be high, was situated. The first Ptolemy began the project, and the second Ptolemy (Ptolemy II Philadelphus) completed it, at a total cost of 800 talents. It took 12 years to complete and served as a prototype for all later lighthouses in the world. The light was produced by a furnace at the top and the tower was built mostly with solid blocks of limestone. The Pharos lighthouse was destroyed by an earthquake in the 14th century, making it the second longest surviving ancient wonder, after the Great Pyramid of Giza. A temple of Hephaestus also stood on Pharos at the head of the mole. In the 1st century, the population of Alexandria contained over 180,000 adult male citizens, according to a census dated from 32 AD, in addition to a large number of freedmen, women, children and slaves. Estimates of the total population range from 216,000 to 500,000, making it one of the largest cities ever built before the Industrial Revolution and the largest pre-industrial city that was not an imperial capital. Geography Alexandria is located in the country of Egypt, on the southern coast of the Mediterranean. It is in the Far West Nile delta