It was found in 1886 on via Labicana, not far away from the coliseum on the slopes of the esquiline hill.
The ancient regional catalogues –lists of sites within an Augustan region- dating back to 2000 years ago, reported the presence of an Iseum, or temple of Isis. The head was in the temple, I believe.
It’s exquisite and very charming. Now it’s location is the Centrale Montemartini museum in Rome.
Centrale Montemartini museum