This ancient building is located not far from the Roman Agora. It was built in the II century BC The tower was built by the Syrian astronomer Andronicus Kirrestskim. The height of the octagonal tower is 12 meters and the diameter - 8 meters. The outer tower frieze depicts eight winds blowing in Athens. Vane is designed as a Triton.

Inside the tower is a state water clock (clepsydra), and on the outside walls are still visible sundial.