Calabarzon (/kɑːlɑːbɑːrˈzɒn/), formally known as the Southern Tagalog Mainland, is an administrative region in the Philippines, designated as Region IV-A. The region comprises five provinces: Batangas, Cavite, Laguna, Quezon, and Rizal; and one highly urbanized city, Lucena. The region is the most populous region in the Philippines according to the Philippine Statistics Authority, having over 14.4 million inhabitants in 2020, and is also the country's second most densely populated after the National Capital Region.