The _new_ castles of Europe and Asia are constructed on either continent upon the foundations of two celebrated temples of Serapis and Jupiter Urius.

The _old_ castles, a work of the Greek emperors, command the narrowest part of the channel, in a place where the opposite banks advance within five hundred yards of each other.

These fortresses were destroyed and strengthened by Mahomet the Second when he meditated the siege of Constantinople; but the Turkish conqueror was most probably ignorant that near two thousand years before his reign Darius had chosen the same situation to connect the two continents by a bridge of boats.

At a small distance from the old castles we discover the little town of Chrysopolis or Scutari, which may almost be considered as the Asiatic suburb of Constantinople.

The Bosphorus, as it begins to open into the Propontis, passes between Byzantium and Chalcedon.