323 Park Avenue South, a new, yet-to-be-built development, will be a boutique condominium that will be both modern and chic inside and out. Famed architects Gwathmey and Siegel were hired to make 323 Park Avenue South a cutting-edge building that meets or exceeds the standards of luxury in the current Manhattan condo listings. The luxury condos for sale at 323 Park Avenue South will feature high-end fixtures such as wide plank hardwood flooring, floor-to-ceiling windows, and marble bathrooms with heated floors.