The Smithsonian Castle is one of the most recognizable buildings in the world. Designed by James Renwick, Jr. and completed in 1855, it originally housed all of the new Institution's operations, including laboratories, lecture halls, museum galleries, and Secretary Joseph Henry's private apartments. While the rapid expansion of the Smithsonian's collections and areas of research has prompted the Smithsonian campus to grow, this unique Gothic Revival structure remains the symbol of the Institution.
Take a Tour: http://www.si.edu/ahhp/sibtour_start