The Upper East Side is the most densley populated part of Manhattan. Museum Mile along Fifth Avenue presents a grand series of limestone and sandstone mansions along with many the city's most prestigious co-operatives.
The area between Fifth and Lexington Avenues is filled with large brownstones, canopied prewar apartment buildings, and some of New York's most exclusive shopping and expensive restaurants.
From Lexington Avenue to the East River is a greater mix of housing types, with the addition of walk-up buildings as well as (particularly along First, York and East End Avenues) many large modern apartment buildings. Many of these buildings have swimming pools, gyms and parking facilities.
Because of the dense population of the area, there are numerous restaurants, bars and service businesses. The Upper East Side is always a Best Bet for finding almost any kind of housing you want-- from the least expensive to the ultra-luxury.