The Roman Agora (Market of Caesar and Augustus) is located on the north side of the Acropolis, and a short distance to the east of the Greek Agora, with which it was connected by a paved street. An inscription (IG II2 3174) on the architrave of the monumental Gate of Athena Archegetis (“Athena the Leader”) tells us that Julius Caesar and Augustus provided the funds for its construction in the 1st century B.C. The Roman Agora consists of a large, open-air courtyard surrounded by colonnades on all four sides. On the eastern side, there were also a series of shops. On the southern side was a fountain. The main entrance was on the west (Gate of Athena Archegetis), and there was a second entrance (or propylon) on the east, leading up to a public latrine and the “Tower of the Winds.” The Roman Agora apparently became the main market of the city, taking over many of the commerical functions of the Greek Agora, which had become something of a museum (or archaeological park) by that time.
The Tower of the Winds, also called horologion (timepiece), is an octagonal Pentelic marble clocktower on the Roman agora in Athens. The structure features a combination of sundials, a water clock and a wind vane. It was supposedly built by Andronicus of Cyrrhus around 50 BCE, but according to other sources might have been constructed in the 2nd century BCE before the rest of the forum.
The 12-metre-tall structure has a diameter of about 8 metres and was topped in antiquity by a weathervane-like Triton that indicated the wind direction. Below the frieze depicting the eight wind deities — Boreas (N), Kaikias (NE), Eurus (E), Apeliotes (SE), Notus (S), Livas (SW), Zephyrus (W), and Skiron (NW) — there are eight sundials. In its interior, there was a water clock (or clepsydra), driven by water coming down from the Acropolis. Recent research has shown that the considerable height of the tower was motivated by the intention to place the sundials and the wind-vane at a visible height on the Agora, making it effectively an early example of a clocktower. According to the testimony of Vitruvius and Varro, Andronicus of Cyrrhus designed the structure. The tower’s columns bore capitals of a design now known as “Tower of the Winds Corinthian,” although they lack the volutes ordinarily found in Corinthian capitals.
In early Christian times, the building was used as the bell-tower of a Byzantine Church. Under Ottoman rule it became a tekke and was used by whirling dervishes. At that time it was buried up to half its height, and traces of this can be observed in the interior, where Turkish inscriptions may be found on the walls. It was fully excavated in the 19th century by the Archaeological Society of Athens.
The design of the 18th-century Radcliffe Observatory in Oxford, England, is based on the Tower of the Winds, as is the mausoleum of the founder of the Greek National Library Panayis Vagliano at West Norwood Cemetery, London. It has also inspired the 15th-century Torre del Marzocco in Livorno. There is a similar tower in Sevastopol, built in 1849. Another building based on the design of the Tower of the Winds is the Temple of the Winds, which stands in the grounds of Mount Stewart near Newtownards in Northern Ireland.