The Colossus of Nero was a 30-metre bronze statue that the Emperor Nero created in the vestibule of his Domus Aurea, the imperial villa complex which spanned a large area from the north side of the Palatine Hill, across the Velian ridge to the Esquiline Hill. It was modified by Nero's successors into a statue of the sun god Sol. The statue was eventually moved to a spot outside the Flavian Amphitheatre, which became known, by its proximity to the Colossus, as the Colosseum.
The last mention of the Colossus is in an illuminated manuscript from the late 4th century AD. The statue disappeared sometime afterwards, likely toppled by an earthquake or destroyed during the Sack of Rome, although some sources indicate the statue may have remained standing as late as the 7th century AD. Today, the only remnants of the statue are some concrete blocks that once made up the foundation of its marble pedestal.
Wikipedia https://en.wikipedia.org/wiki/Colossus_of_Nero
Official Website https://www.info.roma.it/monumenti_dettaglio.asp?ID_schede=538
Address Piazza del Colosseo, Roma 00184, Italy
Coordinates 41°53'27.145" N 12°29'27.574" E