Clock of Andronikos Kyrrestos

Clock of Andronikos Kyrrestos, originally uploaded by Ava Babili.

This is located outside the western entrance to the Roman Market. It was constructed in the 1st century B.C. by the astronomer Andronikos from Kyrrhos in Macedonia and is shaped like an octagonal tower. It served as a form of meteorological station since it combined a sundial and water clock and also had a weathervane to show the direction of the wind. Each face is adorned with a relief representing the wind blowing from that direction, hence its nickname in Greek "aerides" meaning "the winds".

Same building as here and here