La Paz, officially Nuestra Señora de La Paz, is the seat of government and de facto capital of the Plurinational State of Bolivia. With an estimated 816,044 residents as of 2020, La Paz is the third-most populous city in Bolivia. Its metropolitan area, which is formed by La Paz, El Alto, Achocalla, Viacha, and Mecapaca makes up the second most populous urban area in Bolivia, with a population of 2.2 million, after Santa Cruz de la Sierra with a population of 2.3 million. It is also the capital of the La Paz Department.