Forum Romanum. western part, south-eastern view from the Capitoline Hill to the Palatine Hill, Milliarium Aureum, Temple of Saturn and Temple of Vespasian and Titus.
Forum Romanum. western part, south-eastern view from the Capitoline Hill to the Palatine Hill, Umbilicus urbis Romae, Milliarium Aureum, Temple of Saturn and Temple of Vespasian and Titus.
The Temple of Saturn was completely reconstructed by Munatius Plancus in 42 BC. The present ruins represent the third incarnation of the Temple of Saturn, replacing a second incarnation that had been destroyed by the fire of Carinus in AD 283. Gradual collapse has left nothing but the remains of the front portico standing.
The Milliarium Aureum (Classical Latin: golden milestone) was a monument, probably of marble or gilded bronze, erected by the Emperor Caesar Augustus near the Temple of Saturn in the central Forum of Ancient Rome. All roads were considered to begin at this monument and all distances in the Roman Empire were measured relative to it. On it perhaps were listed all the major cities in the empire and distances to them, though the monument's precise location and inscription remain matters of debate among historians.
Augustus, as curator viarum, erected the monument in 20 BC. It probably received the name Milliarium Aureum soon after its inauguration. It symbolized the starting point of the Roman road system to the rest of Italy and to all the imperial possessions.
It is certain that it was "hard by [under] the Temple of Saturn at the head of the Roman Forum", but its exact location is still unknown. Due to archaeological data from excavations by Kähler in 1959, which seem to confirm data from excavations by Bunsen in 1833, many scholars now believe that it was located at the southeast corner of the podium of the Rostra Augusti on a symmetrical axis with the Umbilicus Urbis Romae.
More on https://en.wikipedia.org/wiki/Capitoline_Hill , https://en.wikipedia.org/wiki/Palatine_Hill , https://en.wikipedia.org/wiki/Milliarium_Aureum , https://en.wikipedia.org/wiki/Temple_of_Saturn , https://en.wikipedia.org/wiki/Temple_of_Vespasian_and_Titus
picture generously provided by Rudolf Kaufmann (2015)