the Tower of the Winds

Considered the world's first meteorological station the Tower of the Winds or the Horologion of Andronikos Kyrrhestes, is an octagonal Pentelic marble clocktower in the Roman Agora in Athens between the quarters of Plaka and Monastiraki. The building functioned as a horologion or "timepiece".

More than 2,000 years old, the tower has eight sides corresponding to the eight principle winds, a combination of sundials, a wind vane to show the direction of wind and an interior water clock that in antiquity could be read even in darkness. It was designed by Andronicus of Cyrrhus around 50 BC. According to other sources, might have been constructed in the 2nd century BC before the rest of the forum.

The building became better known outside Greece when details were published in London in the first volume of The Antiquities of Athens (which also described four other ancient Greek buildings). It had been surveyed by James "Athenian" Stuart and Nicholas Revett on an expedition in 1751–54.

Several buildings are based on the design of the Towers of the Winds, including:

The 18th-century Tower of the Winds on top of the Radcliffe Observatory in Oxford, England,
St Pancras Church (1822) designed by William Inwood and his son Henry William Inwood, located in Euston, London. This is a unique Greek-revival church, that features two sets of Caryatids and a tower that was based on the classical Tower of the Winds.
The Daniel S. Schanck Observatory (1865) an early astronomical observatory at Rutgers University in New Brunswick, New Jersey.
The mausoleum of the founder of the Greek National Library Panayis Vagliano at West Norwood Cemetery, London.
The 15th-century Torre del Marzocco in Livorno.
The tower on St Luke's Church, West Norwood, in London, designed by Francis Octavius Bedford after he visited Athens on a Society of Dilettanti scholarship circa 1810.
A similar tower in Sevastopol, built in 1849.
The Temple of the Winds, which stands in the grounds of Mount Stewart near Newtownards in Northern Ireland.
The Carnaby Temple near Carnaby, East Riding of Yorkshire, built in 1770.
The Maitland Robinson building in Downing College, Cambridge, designed by Quinlan Terry in 1992.
The "Storm Tower" in Bude, Cornwall (1835), by George Wightwick

The Tower of the Winds was based on Eratosthenes’s eight-wind system, with each side of the octagonal tower facing a wind direction. On the sides facing the sun, are the lines of a sundial. In antiquity, the tower was surmounted by a weather vane in the form of a bronze Triton and contained a water clock to record the time when the sun was not shining. Located in the Roman Agora (market place), the tower was of great value for the merchants who used it to read the weather and predict when their goods would arrive by sea.

Aristotle’s wind rose

The Greek philosopher Aristotle identified ten distinct winds—two north-south winds (Aparctias, Notos) and four sets of east-west winds blowing from different latitudes—the Arctic circle (Meses, Thrascias), the summer solstice horizon (Caecias, Argestes), the equinox (Apeliotes, Zephyrus) and the winter solstice (Eurus, Lips). Aristotle explained that each wind had different meteorological properties. For instance, winds on the NW-SE axis are generally dry, while the NE-SW winds are wet. N and NNE winds bring snow, while those from the whole northwestern sector (NW, NNW, N) bring hurricanes.

However, Aristotle's system was asymmetric. To restore balance, Timosthenes, a Greek navigator and geographer, added two more winds to produce the classical 12-wind rose. But another Greek geographer, Eratosthenes of Cyrene, realizing that many winds presented only slight variations, reduced the twelve winds down to eight principal winds, marking a significant step towards the evolution of the 8-point compass rose that’s still used in almost all navigation systems, including nautical charts, maps, compass and even GPS!