The Smithsonian Institution Building—known as the Castle—will close Wednesday, Feb. 1, for its first major renovation in more than 50 years. The renovation is expected to last about five years, and will include restoring the Great Hall to its original appearance, expanding and moving the café and shop, and creating more space for public programming, as well as exterior work and system replacement. During construction, the Enid A. Haupt Garden behind the Castle will remain open. The Smithsonian’s Visitor Center will expand its online services, with a virtual Visitor Center website launching in early February.