The Smithsonian Institution Building (Castle) is a National Historic Landmark on the National Mall. When completed in 1855, the Castle housed all the Smithsonian’s operations including research and administrative offices, lecture and exhibition halls, library, laboratories, collections storage, and living quarters. The Castle’s interior spaces have undergone many modifications as the Smithsonian expanded. The Castle closed to the public in 2023 in preparation for a comprehensive rehabilitation project. This project will restore the building exterior and interior, install efficient building systems, update the Visitor Center and amenities, mitigate seismic vulnerability, and revitalize an iconic building for a century of further use.

Come enjoy a behind-the-scenes hardhat tour of the ongoing construction with the Smithsonian Institution. The Castle is not accessible, and tour participants must be able to climb stairs. Tour participants will also be required to have full Personal Protective Equipment (hardhat, high visibility vest, glasses, proper footwear, and long pants). If you need to borrow PPE, please reach out to info@aptdc.org.

Registration will open Tuesday, February 10th