As more and more condos and high-rises sprout across the city, it’s easy to forget about New York’s magnificent mansions of yesteryear. Touring the splendid home of American industrialist Henry Clay Frick (1849-1914) offers a glimpse into old New York, and into Mr. Frick’s superb art collection, which spans several centuries and includes decorative arts, paintings, and sculptures. The mansion sits on Fifth Avenue, fronted by a leafy garden with magnolia trees. Inside, the works are beautifully displayed among sixteen galleries. Mr. Frick amassed the collection and bequeathed it to the public upon his death so that future generations could enjoy it and learn from it, just as he had. The collection has since been expanded, and today includes French 18th century furniture, Chinese porcelain vases, and pieces by El Greco, Goya, Degas, Rembrandt, Velazquez, Titian, and Vermeer. When you need a breather, head to the soothing, skylit Garden Court, where you can relax around a gurgling fountain