The Bosphorus Strait, view to east from Palace Point, Istanbul, Turkey.

The Bosphorus Strait, at its narrow point, where Sultan Mehmed II built the Anadolu and Rumeli Hissar fortresses.

The Bosphorus Strait, where it enters the Black Sea.

The Golden Horn, Istanbul’s natural harbor. Turkey.

The Theater at Ephesus (Efes), Turkey. Farmland in background was once the harbor, which silted up.