Flag of Buenos Aires Province

The flag of Buenos Aires Province, Argentina, was created by students and officially adopted by Provincial Law 11.997 on August 12, 1997, after being chosen among other designs by vote of the educative community in which 270,000 students aged 12–18 took part in over 2 years, supported by specialists and parents. There were 81,525 proposals, 32 of which were selected from all 16 regions along 1995–96.

Source: Wikipedia — Flag of Buenos Aires Province (CC BY-SA 4.0)