The Umbilucus Urbi of the City of Rome, the designated centre of the city from which and to which all distances in Rome and the Roman Empire were measured, is situated in the Roman Forum. It was built between the Basilica Aemilia, which pre-dates it, and the Basilica Julia, which does not, in the late Republican period. The Rostra, the platform from which orators addressed the Roman mob, were built overlooking it. Roman Forum with Palatine Hill in the background. ... The Basilica Aemilia was erected in 179 BC by the censors Marcus Aemilius Lepidus (after whom the basilica is named) and Marcus Fulvius Nobilior, completely rebuilt over two decades and dedicated in 34 BC, restored after a fire by Augustus in 14 BC, and then again in AD 22 on... The Basilica Julia, named after Julius Caesar, who dedicated it in 46 BC from the spoils of the Gallic War, the Basilica Julia was completed by Augustus, but burned shortly afterward and was not rededicated for another twenty years, in 12 AD. It again was rebuilt by Diocletian after the... The base of the column dedicated in 303, during the visit of emperor Diocletian in Rome, in occasion of the ten years of the institution of the Tetrarchy. ...

Originally covered in marble, the umbilicus is now a forlorn-looking brick structure some two metres high and two metres in diameter.