Museo Lázaro Galdiano

Imagine 37 rooms in a well-preserved 19th-century mansion bulging with artworks -- including many by the most famous Old Masters of Europe. Visitors usually take the elevator to the top floor and work down, lingering over such artifacts as 15th-century hand-woven vestments, swords and daggers, royal seals, 16th-century crystal from Limoges, Byzantine jewelry, Italian bronzes from ancient times to the Renaissance, and medieval armor.

One painting by Bosch evokes his own peculiar brand of horror, the canvas peopled with creepy fiends devouring human flesh. The Spanish masters are the best represented -- among them El Greco, Velázquez, Zurbarán, Ribera, Murillo, and Valdés-Leal.

One section is devoted to works by the English portrait and landscape artists Reynolds, Gainsborough, and Constable. Italian artists exhibited include Tiepolo and Guardi. Salon 30 -- for many, the most interesting -- is devoted to Goya and includes paintings from his "black period."

This off-the-beaten-track museum is a gem and usually enjoyably underpopulated, a nice contrast to the overcrowded Prado, Thyssen, and Reina Sofía museums.