With more than 7,000 paintings, the Prado is one of the most important repositories of art in the world. It began as a royal collection and was enlarged by the Habsburgs, especially Charles V, and later the Bourbons. In paintings of the Spanish school the Prado has no equal; on your first visit, concentrate on the Spanish masters (Velázquez, Goya, El Greco, and Murillo).Major Italian works are exhibited on the ground floor. You'll see art by Italian masters -- Raphael, Botticelli, Mantegna, Andrea del Sarto, Fra Angelico, and Correggio. The most celebrated Italian painting here is Titian's voluptuous Venus being watched by a musician who can't keep his eyes on his work.The Prado is a trove of the work of El Greco (ca. 1541-1614), the Crete-born artist who lived much of his life in Toledo. You can see a parade of "The Greek's" saints, Madonnas, and Holy Families -- even a ghostly John the Baptist.You'll find a splendid array of works by the incomparable Diego Velázquez (1599-1660). The museum's most famous painting, in fact, is his Las Meninas, a triumph in the use of light effects. The faces of the queen and king are reflected in the mirror in the painting itself. The artist in the foreground is Velázquez, of course.The Flemish painter Peter Paul Rubens (1577-1640), who met Velázquez while in Spain, is represented by the peacock-blue Garden of Love and by the Three Graces. Also noteworthy is the work of José Ribera (1591-1652), a Valencia-born artist and contemporary of Velázquez whose best painting is the Martyrdom of St. Philip. The Seville-born Bartolomé Murillo (1617-82) -- often referred to as the "painter of Madonnas" -- has three Immaculate Conceptions on display.The Prado has an outstanding collection of the work of Hieronymus Bosch (1450?-1516), the Flemish genius. The Garden of Earthly Delights, the best-known work of "El Bosco," is here. You'll also see his Seven Deadly Sins and his triptych The Hay Wagon. See also The Triumph of Death, by another Flemish painter, Pieter Breughel the Elder (ca. 1525-69), who carried on Bosch's ghoulish vision.Francisco de Goya (1746-1828) ranks along with Velázquez and El Greco in the trio of great Spanish artists. Hanging here are his unflattering portraits of his patron, Charles IV, and his family, as well as the Clothed Maja and the Naked Maja. You can also see the much-reproduced Third of May (1808), plus a series of Goya sketches (some of which, depicting the decay of 18th-c. Spain, brought the Inquisition down on the artist) and his expressionistic "black paintings."