Valenzuela Foundation Day is observed in Valenzuela City, located in the National Capital Region of the Philippines, every November 12. This holiday commemorates the founding of the town originally known as Polo, which was established on November 12, 1623, by Governor General Alonso Fajardo de Entenza. The day also honors the city’s namesake, Pío Valenzuela, a key figure in the Philippine Revolution against Spanish rule. Celebrations typically include various local events and activities that reflect the city's rich history and cultural heritage. Valenzuela Foundation Day should not be confused with Valenzuela Day, celebrated on February 14, which marks the city's conversion into a highly urbanized city. The history of Valenzuela is marked by significant events, including the town's struggles during the British occupation and World War II, as well as its eventual reunification in 1963.