...on land depopulated by Nero's fire. So, if the Colosseum as a symbol of Rome and an iconic circle isn't poetic enough for you, there is also the metaphor of destruction/fire leading to creation as in "CD burning."
While you're technically correct, you're still incorrect.
The area devastated by the Great Fire (allegedly started by Nero) was used to build Nero's Golden House (Domus Aurea) first. After his death, most of the Golden House complex was demolished and it was only then that the infilled artificial lake of the Golden House was chosen as the site for the Colosseum.