The convent of the Descalzas Reales ('Royal Barefoot Nuns') is the most complete 16th-century building in Madrid and still houses a cloistered community. It was originally built as a palace for Alonso Gutiérrez, treasurer of Charles V, but was converted into a convent in 1556-64 by Antonio Sillero and Juan Bautista de Toledo after Philip II's widowed sister Joanna of Austria decided to become a nun.

Founded with royal patronage, the Descalzas became the preferred destination of the many widows, younger daughters and other women of the royal family and high aristocracy of Spain who entered religious orders. Hence it also acquired an extraordinary collection of works of art - paintings, sculptures, tapestries and objets d'art - given as bequests by the novices' families.

Equally lavish is the baroque decoration of the building itself, belying its sternly austere façade, with a grand painted staircase, frescoed ceilings and 32 chapels, only some of which can be visited.