For beauty & photography, SoHo delivers.
Block after block of beautiful 19th-century cast-iron facades — and beneath them, flagship stores and the city's densest shopping. The taste move is to separate the architecture from the retail: walk Greene Street and Mercer Street (the best-preserved cast-iron blocks, with their Belgian-block paving) early on a weekday morning, when the shutters are still down and the facades and fire escapes read as the open-air museum they are. By weekend afternoon those same streets are a shoulder-to-shoulder shopping crush and the architecture disappears behind the crowd. Lovely to walk even if you buy nothing; light on classic sights.