The National Gallery’s I.M. Pei-designed East Building turns 25 this year. “Pei has staked his career on bold visions and controversial stands. Architects have voted the building one of the 10 best in America. Pei has just admitted to ‘great affection’ for his creation, as well he should. The East Building’s extraordinary geometries and modern spirit established Pei as a 20th-century master. Success here also propelled him on to the challenge of his career, the historic remaking of France’s grand Louvre museum.”