A couple of blocks north of San Ginés at Plaza de las Descalzas Reales 3 is one of the hidden treasures of Madrid, the Monasterio de las Descalzas Reales (wwww.patrimonionacional.es; mSol/Callao). This was founded in 1557 by Juana de Austria, daughter of the Emperor Carlos V, sister of Felipe II, and, at the age of 19, already the widow of Prince Don Juan of Portugal. In her wake came a succession of titled ladies (Descalzas Reales means "Barefoot Royals"), who brought fame and, above all, fortune to the convent, which is unbelievably rich, though beautiful and tranquil, too. It is still in use, with shoeless nuns tending patches of vegetable garden.

Whistle-stop guided tours (Tues– Thurs & Sat 10.30am–12.45pm & 4–5.45pm, Fri 10.30am–12.45pm, Sun & some holidays 11am–1.45pm; €5, joint ticket with Convento de la Encarnación €6, valid for a week) conduct visitors (usually in Spanish only) through the cloisters and up an incredibly fancy stairway to a series of chambers packed with art and treasures of every kind. The former dormitories are perhaps the most outstanding feature, decorated with a series of Flemish tapestries based on designs by Rubens and a striking portrait of St Francis by Zurbarán. These were the sleeping quarters for all the nuns, including St Teresa of Ávila for a time, although the empress María of Germany preferred a little more privacy and endowed the convent with her own luxurious private chambers. The other highlight of the tour is the Joyería (Treasury), piled high with jewels and relics of uncertain provenance. The nuns kept no records of their gifts, so no one is quite sure what many of the things are – there is a bizarre cross-sectional model of Christ – nor which bones came from which saint. Whatever the case, it's an exceptional hoard.

Over towards the Palacio Real in Plaza de la Encarnación is the Convento de la Encarnación (same hours as above; €3.60, joint ticket with Monasterio de las Descalzas Reales €6, valid for a week; www.patrimonionacional.es; MÓpera). This was founded a few years after Juana's convent, by Margarita, wife of Felipe III, though it was substantially rebuilt towards the end of the eighteenth century. It houses an extensive but somewhat disappointing collection of seventeenth-century Spanish art, and a wonderfully bizarre library-like reliquary, reputed to be one of the most important in the Catholic world. The most famous relic housed here is a small glass bulb said to contain the blood of the fourth-century doctor martyr, St Pantaleon, whose blood supposedly liquefies at midnight on the eve of his feast day (July 26). The tour ends with a visit to the Baroque-style church featuring a beautifully frescoed ceiling.