The Tower of the Winds, known as the Ωρολόγιο του Κυρρήστου in Greek, and by other names, is an octagonal Pentelic marble tower in the Roman Agora in Athens, named after the eight large reliefs of wind gods (in the form of young winged men and old men) around its top. Its date is uncertain, but was completed by about 50 BC, at the latest, as it was mentioned by Varro in his De re Rustica of about 37 BC. It is "one of the very small number of buildings from classical antiquity that still stands virtually intact", as it has been continuously occupied for a series of different functions.
Formerly topped by a wind vane, it is the only surviving horologium or clock tower from classical antiquity. It also housed a large water clock and incorporated sundials placed prominently on its exterior faces; "citizens were thus able by using this building to orient themselves in space and time. Architecture, sculpture and the new science were perfectly integrated".
