The Lower East Side (or simply LES) is a center of all things cool: arts and nightlife, restaurants and cafés, boutiques and cool hair salons. What was once the "Gateway to America" (and home of waves of Irish, German, Jewish, Hispanic, and Chinese immigrants) is now a quickly gentrifying neighborhood where modern high-rises, the ultracontemporary New Museum, and low-key restaurants exist in the same corner of Manhattan.
On Saturday night, the scene can be as raucous as in a college town, especially on Rivington and Orchard streets, but Ludlow Street, one block east of Orchard, has become the main drag for twentysomethings with attitude, its boutiques wedged between bars and small restaurants.
The best time to experience the neighborhood's past is by day. The excellent Lower East Side Tenement Museum movingly captures the immigrant legacy of tough times and survival instincts. You might not find many pickles being sold from barrels anymore, but this remains a good place to nosh on typical Jewish food from Katz's Delicatessen or Russ & Daughters.