Centro is a district of Madrid, Spain. It is approximately 5.23 km2 in size. It has a population of 149,718 people and a population density of 28,587/km2. It roughly corresponds to the bulk of the housing formerly enclosed by the so-called Walls of Philip IV. The district is made up of the neighbourhoods of Cortes, Embajadores, Justicia, Universidad, Palacio and Sol.