In the early twenty-first century, the city continued to address new challenges: keeping the population within the urban core (Madrid is the municipality of Spain in which the increase in house prices has been higher) expansion of the city (with the creation of new districts following the Urban Action Plan: Widening of Vallecas, Widening Carabanchel, Montecarmelo, Arroyo del Fresno, Las Tablas, Sanchinarro, ...); Valdebebas remodeling of the historic center, absorption and integration of immigrants who came to the city.
On March 11, 2004 the city suffered a series of attacks with rucksack bombs placed on four trains of the suburban railway network. The bombings, the biggest suffered in Spain and the European Union, claimed the lives of 191 people and wounded more than 1900.23 On March 11, 2007, just three years later, the Kings of Spain (Juan Carlos I and Queen Sofia Greece) inaugurated at the roundabout of Charles V a memorial to víctimas.24
On December 30, 2006, ETA bomb explodes in the parking terminal 4 at Madrid-Barajas airport, killing two people. Since the attacks against Luis Carrero Blanco (1973) and the bar of the E Street (1974), opposite the General Directorate of Security, Madrid has experienced much of the activity of this terrorist group.