El Pueblo de Los Ángeles Historical Monument, also known as Los Angeles Plaza Historic District and formerly known as El Pueblo de Los Ángeles State Historic Park, is a historic district taking in the oldest section of Los Angeles, known for many years as El Pueblo de Nuestra Señora la Reina de los Ángeles del Río de Porciúncula. The district, centered on the old plaza, was the city's center under Spanish (1781–1821), Mexican (1821–1847), and United States rule through most of the 19th century. The 44-acre park area was designated a state historic monument in 1953 and listed on the National Register of Historic Places in 1972.

Los Angeles, often referred to by its initials L.A., is the most populous city in the U.S. state of California. With roughly 3.9 million residents within the city limits as of 2020, Los Angeles is the second-most populous city in the United States, behind only New York City; it is also the commercial, financial and cultural center of Southern California. Los Angeles has an ethnically and culturally diverse population, and is the principal city of a metropolitan area of 13.2 million people. Greater Los Angeles, which includes the Los Angeles and Riverside–San Bernardino metropolitan areas, is a sprawling metropolis of over 18 million residents.