San Isidro is a city in Greater Buenos Aires. It is located 27.9 km from the Autonomous City of Buenos Aires. It ranks as the province's most affl…San Isidro is a city in Greater Buenos Aires. It is located 27.9 km from the Autonomous City of Buenos Aires. It ranks as the province's most affluent neighborhood. In 2007, San Isidro celebrated its 300 years of existence with different celebrations taking place in the Hippodrome and in other venues. The settlement was first incorporated in 1784 as the Alcaldía de la Hermandad and was granted municipality status by the province in 1850. It maintains sister city relationships with Herzliya, Israel; Nagoya, Japan; and San Isidro, Peru.