Book excerpt: Gwathmey Siegel’s buildings represent the pinnacle of late-twentieth and early-twenty-first-century modernist design, and this new volume focuses on a single architectural masterpiece: 400 Fifth Avenue. Designed by the award-winning architectural firm Gwathmey Siegel & Associates Architects and soaring sixty stories above Fifth Avenue, 400 Fifth Avenue seamlessly integrates an unparalleled collection of spectacular condominium tower residences with the world-class, five-star Setai Fifth Avenue hotel, providing a one-of-a-kind architectural icon in the heart of midtown Manhattan.