The Horologium Augusti or Solarium Augusti was an ancient monument of the Campus Martius built during the reign of Augustus. In theory, it functioned as a giant solar marker. An obelisk relocated to Rome from Heliopolis served as the gnomon. The obelisk today stands in the Piazza di Monte Citorio.
Description via Pleiades. Coordinates and heritage data from the Atika atlas.
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