Coke-and-steel baron Henry Clay Frick (1849-1919) amassed this superb art collection far from the soot and smoke of Pittsburgh, where he made his fortune. The mansion was designed by Thomas Hastings and built in 1913-14. It opened as a museum in 1935 and expanded in 1977, but still resembles a gracious private home, albeit one with bona fide masterpieces in almost every room. Édouard Manet's The Bullfight (1864) hangs in the Garden Court. Two of the Frick's three Vermeers -- Officer and Laughing Girl (circa 1658) and Girl Interrupted at Her Music (1660-61) -- hang by the front staircase. Fra Filippo Lippi's The Annunciation (circa 1440) hangs in the Octagon Room. Gainsborough and Reynolds portraits are in the dining room; canvases by Gainsborough, Constable, Turner, and Gilbert Stuart are in the library; and several Titians (including Portrait of a Man in a Red Cap, circa 1516), Holbeins, a Giovanni Bellini (St. Francis in the Desert, circa 1480), and an El Greco (St. Jerome, circa 1590-1600) are in the "living hall." Nearly 50 additional paintings, as well as much sculpture, decorative arts, and furniture, are in the West and East galleries. Three Rembrandts, including The Polish Rider (circa 1655) and Self-Portrait (1658), as well as a third Vermeer, Mistress and Maid (circa 1665-70), hang in the former; paintings by Whistler, Goya, Van Dyck, Lorrain, and David in the latter. The free "ArtPhone" audio tour guides you through the museum at your own pace and is available in several languages. When you're through, the tranquil indoor court with a fountain and glass ceiling is a lovely spot for a respite. COST: $12. Subway: 6 to 68th St./Hunter College.