Pilar is a city in the province

Provinces of Argentina

Argentina is subdivided into twenty-three provinces and one autonomous city...

 of Buenos Aires

Buenos Aires Province

The Province of Buenos Aires is the largest and most populous province of Argentina. It takes the name from the city of Buenos Aires, which used to be the provincial capital until it was federalized in 1880...

, Argentina

Argentina

Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

. It has a population of more than 226,000 inhabitants as per the . Pilar is part of the Greater Buenos Aires

Greater Buenos Aires

Greater Buenos Aires is the generic denomination to refer to the megalopolis comprising the autonomous city of Buenos Aires and the conurbation around it, over the province of Buenos Aires—namely the adjacent 24 partidos or municipalities—which nonetheless do not constitute a single administrative...

 urban conurbation and is the head of the administrative division of Pilar Partido

Pilar Partido

Pilar Partido is a partido located in the northern part of Greater Buenos Aires in Buenos Aires Province, Argentina.The provincial subdivision has a population of about 232,000 inhabitants in an area of 352 km², and its capital city is Pilar, which is located around 45km from Buenos Aires.It has...

. It is well known for its heavy metal band Jheronimus Bosch.

Pilar is the site where the Treaty of Pilar

Treaty of Pilar

The Treaty of Pilar was a pact signed among the rulers of the Argentine provinces of Santa Fe, Entre Ríos and Buenos Aires, which is recognized as the foundation of the federal organization of the country...

 was signed on February 23, 1820, establishing the basis for Argentine federalism. Because of this relevant event, the city of Pilar is acknowledged as the "Cradle of National Federalism". This Treaty marked the end of the war between the provinces of Entre Ríos

Entre Ríos Province

Entre Ríos is a northeastern province of Argentina, located in the Mesopotamia region. It borders the provinces of Buenos Aires , Corrientes and Santa Fe , and Uruguay in the east....

 and Santa Fe

Santa Fe Province

The Invincible Province of Santa Fe, in Spanish Provincia Invencible de Santa Fe , is a province of Argentina, located in the center-east of the country. Neighboring provinces are from the north clockwise Chaco , Corrientes, Entre Ríos, Buenos Aires, Córdoba, and Santiago del Estero...

 against Buenos Aires.

Pilar has experienced a huge demographic expansion, specially in the last decade, that has brought with it rapid economic development. The city has become known as an exclusive residential hideaway from downtown Buenos Aires

Buenos Aires

Buenos Aires is the capital and largest city of Argentina, and the second-largest metropolitan area in South America, after São Paulo. It is located on the western shore of the estuary of the Río de la Plata, on the southeastern coast of the South American continent...

 where many affluent families own houses in gated communities.