The new castles of Europe and Asia are constructed, on either continent, upon the foundations of two celebrated temples, of Serapis and of 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 paces of each other.

These fortresses were destroyed and strengthened by Mahomet the Second, when he meditated the siege of Constantinople: [8] 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.

[9] 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.