It starts at the Puerta del Sol and goes on for 11 kilometres (6.8 mi), to the northeastern outskirts of the city.

Henry David Inglis described it in 1837 as "long, of superb width, and flanked by a splendid range of unequal buildings".

It was the old road which led to the city of Alcalá de Henares (from which it takes the name) and continued to Aragón; today, this route is covered by the A-2 motorway.

Por la calle de Alcalá was a popular cuplé describing a florist selling tuberoses on the street.

Media related to Calle de Alcalá, Madrid at Wikimedia Commons