Alcalá de Henares is a Spanish city in the Community of Madrid. Straddling the Henares River, it is located 31 kilometres to the northe…Alcalá de Henares is a Spanish city in the Community of Madrid. Straddling the Henares River, it is located 31 kilometres to the northeast of the center of Madrid. As of 2018, it has a population of 193,751, making it the region's third-most populated municipality.