SOURCE: John Stuart and Nicholas Revett. The antiquities of Athens, vol. I (London, 1762), ch. III, pl. VII NOTES: This octagonal tower dates from the 1st century BC and was originally the 'Horolgion of Andronykos Kyrrhestes'. It served as a water clock until the 6th century. The sides of the tower indicate the eight points of the Athenian compass, and the eight winds associated with these points are represented allegorically on the marble frieze that runs around the tower.