Since the turn of the century, the Upper East Side has been associated with wealth. Everyone from Andrew Carnegie to Gloria Vanderbilt has resided in this hushed, exclusive neighborhood. Here you’ll find so many mansions and brownstones, clubs and penthouses, that at times the neighborhood resembles an open-air museum.

The wealthy began arriving on the Upper East Side in the late 1800s as an ever-encroaching business tide forced them off the Midtown stretches of 5th Avenue. But the real turning point came in 1905, when steel magnate Andrew Carnegie built his mansion on 5th Avenue at 91st Street. Soon thereafter, one industrialist after another followed suit, until the stretch of 5th Avenue facing Central Park became known as “Millionaire’s Row.” Many of these mansions have since been converted into museums and cultural institutions.

But the Upper East Side is not only about the wealthy. It’s also about more ordinary folk, who—as elsewhere in Manhattan—settled closer to the river. At one time, Madison, Park, and Lexington Avenues were basically middle-class, while the area east of Lexington was working-class and home to recent immigrants. Yorkville, a hamlet established in the 1790s between what are now 83rd and 88th Streets, had an especially large German population.

Stretching roughly from 59th to 100th Street, 5th Avenue to the East River, the Upper East Side’s long residential blocks are pleasant for strolling. Most of the sights and shops are along the north-south avenues rather than the east-west side streets. Madison Avenue is famed for its upscale shops and 5th Avenue is dubbed “Museum Mile” for the 10 museums within its 82nd to 104th street length.