The private collection of financier-collector José Lázaro Galdiano, housed in the early-20th-century palace he built for it on Calle Serrano. Spread across four floors are some 12,000 pieces — paintings (Goya, Bosch, El Greco, Velázquez, Murillo, Constable), Renaissance bronzes, medieval ivories, Islamic ceramics, Italian majolica, and a famously good collection of jewellery and small metalwork.
It is one of Madrid's most rewarding small museums, and almost never crowded. The Goya rooms include the witches' Sabbath painting Witches' Flight and the unsettling early Aquelarre. The palace interior — with painted ceilings, French marble, and gilded woodwork — is itself a primary exhibit. Open every day except Tuesdays; free Sunday afternoons. Allow two hours. Metro Núñez de Balboa or Rubén Darío.