Cooper Hewitt, Smithsonian Design Museum

The Cooper Hewitt is the Smithsonian Institution's only museum outside Washington and the only museum in the United States dedicated exclusively to design. Since 1976 it has occupied Andrew Carnegie's former mansion on Fifth Avenue, a surprisingly restrained brick palace from 1902 that the steel magnate had built as Manhattan's first private house with its own lift and air-conditioning. The collection itself, however, was founded as early as 1896 by the Hewitt sisters, granddaughters of Peter Cooper, as a teaching collection for the Cooper Union. Today it holds more than 215,000 objects, from ancient Egyptian textiles to Vitra chairs, making it one of the largest design collections in the world. Visitors don't just stand in front of vitrines: every guest receives an interactive pen at the entrance to collect objects digitally and then work with them on large touch tables.