Castelo Branco District (Portuguese: Distrito de Castelo Branco [kɐʃˈtɛlu ˈβɾɐ̃ku]) is located in Central Portugal. Its capital is Castelo Branco, which is now also its most populous city, overtaking Covilhã, which was once the largest city, in the late 2010s. It has an area of 6,675 km2 (2,577 sq mi) (4th largest in Portugal), and a population of 225,916 inhabitants.