The Puerta de Alcalá ("Alcalá Gate") is a monument in the Plaza de la Independencia ("Independence Square") in Madrid, Spain, very close to the city centre and several meters away from the main entrance to the Parque del Buen Retiro. The square is bisected by Alcalá street, although the street itself doesn't cross through the monument, and it is the origin of the Alfonso XII, Serrano and Olózaga streets. Its name originates from the old path from Madrid to the nearby town of Alcalá de Henares (Puerta de Alcalá means "Alcalá's Gate" in Spanish).
It was built by order of king Carlos III as a monumental gate in the city wall to pass the road which leads to the city of Alcalá, replacing an older, smaller, gate which stood nearby. It was inaugurated in 1778.