Vanni Archive/Corbis

Not far from ancient Athens’s agora (civic center), the marble clock tower known as the “Tower of the Winds” (shown here, compare with photo of Boreas carving) dates to the second or first century B.C. It originally housed an elaborate water clock and was hung with sundials so passersby could tell the time. Carved on its eight walls are personifications of the eight winds, each blowing from a specific direction.