A neoclassical basilica near La Latina, completed between 1776 and 1784 under Francesco Sabatini. Its dome, 33 metres across and 58 metres high, is the largest in Spain. The museum holds sacred art including works by Goya and Zurbarán. Visits cost €6 and are free on Thursdays; times vary with services, so phone ahead.
Madrid's open-air flea market, held on Sundays and public holidays between Plaza de Cascorro and the streets off Ribera de Curtidores down to Ronda de Toledo. Arrive before 11:00 to avoid the crowds, or come at midday for the atmosphere and stay until it closes at 15:00. Many shops on Ribera de Curtidores also open on weekdays.