Pilar

Pilar, a city northwest of Buenos Aires, is where the Treaty of Pilar was signed in 1820, a foundational document in Argentina's constitutional history that established the basis for the country's federal system. Originally sited on the flood-prone banks of the Luján River, the town was relocated to its current position in the 1800s. Since the 1990s, rapid growth driven by gated-community development has reshaped its character, and it now functions as a significant administrative and commercial hub within Greater Buenos Aires.

• Population81,120
• Nearest water from center1.1 km
• Nearest mountain from center23.7 km
• UNESCO within 50 km1