"he ran a bar around the corner on Lexington Avenue"
View from 50th Street Lexington Ave, facing toward south toward the Chrysler Building
Creative Commons AttributionView from 50th Street Lexington Ave, facing toward south toward the Chrysler Building - Credit: Hidenori Inagaki

Lexington Avenue, abbreviated by New Yorkers to Lex, is located on the East Side of Manhattan.  It runs for just short of 9kms, through Harlem, Carnegie Hill, the Upper East Side, Midtown and Murry Hill, to Gramercy Park.   

It was not included in the original 1811 Manhattan grid plan, but was added in 1832 by developer Samuel Ruggles.