This 1855 Medieval-style building, with its eight crenellated towers and rich red sandstone facade, lives up to its nickname, at least from the exterior. The building closed in February 2023 to begin renovations that will take five years to complete. During the interim, the Enid A. Haupt Garden will remain open, as will several pedestrian paths connecting the National Mall to the National Museum of African Art, and the National Museum of Asian Art. In lieu of the Castle’s visitor center, the Smithsonian Virtual Visitor Center was launched at www.si.edu/visit to provide information and address any questions. Inside the Castle, the remains of Smithsonian benefactor James Smithson are buried in that big crypt in the Mall-side entrance area, which includes a small exhibit about the man.