Illescas is the capital of the region of La Sagra. It is currently a very industrial town which has an interesting past.

Outstanding among its architectural heritage is the parish church of La Asunción, thanks to the conjunction of styles and periods it features; the hospital-sanctuary of La Caridad, from the 16th and 17th centuries, which has a church with a single nave housing five beautiful paintings by El Greco; and the Ugena gate, a Mudejar structure in masonry and brick. Also worth a visit are the small palace in Calle Real, from the 18th century; the baroque convent of the Franciscan Recepcionistas, from the 16th and 18th centuries, and several examples of historicist and modernist architecture.