Alcalá de Henares is one of the easiest day trips from Madrid, well served by the Cercanías suburban rail network. Line C-2 and C-7 both run from Madrid Atocha and Chamartín stations, with departures every 15-20 minutes throughout the day. The journey takes 45-55 minutes and costs a few euros; the Abono Transportes monthly pass covers the trip. The train station is at the edge of the historic centre, a five-minute walk from the main sights.
By car from Madrid, take the A-2 motorway east. There is limited parking in the historic centre; better to use the car parks on the periphery and walk in. The city is also accessible by bus from the Avenida de América bus terminal in Madrid.