Two of the oldest buildings on the National Mall close to the public Monday, Sept. 7, and D.C. residents have through Labor Day weekend to walk through them.

The Smithsonian Castle, completed in 1855, will shut down for its first major renovation in more than 50 years. The closure will last several years, according to the Smithsonian. When the Castle reopens, more than 60% of the building will be accessible to the public, up from 20% before the renovation.

The Arts and Industries Building, the 258,000-square-foot redbrick Victorian next door, also closes Sept. 7 for additional renovations. The Smithsonian Board of Regents voted Aug. 31 to designate the 1881 building as the permanent home of the National Museum of the American Latino, Axios reported. That decision reversed a 2022 recommendation to build a new museum near the Washington Monument.

Jorge Zamanillo, founding director of the Latino museum, said in a statement Aug. 31 that the vote marked "a major milestone in a dream and effort of decades in the making." Congress authorized the museum in 2020. Advocates estimate the project could cost as much as $700 million, according to Hoodline. The Smithsonian has not shared a timeline for opening the museum or details of the renovation.

Before both buildings close, free programming fills the final weekend. The Folklife Festival's "Circus Arts Conservatory" pop-up runs Saturday, Sept. 5, through Sept. 7, from 10 a.m. to 6 p.m. each day at the Arts and Industries Building. More than six free performances run daily.

On Sept. 7, clown story time moves to the National Museum of American History. On Saturday, Sept. 5, from 1 to 2:30 p.m., a free Armenian American wedding celebration takes over the museum's Wallace H. Coulter Plaza, featuring cooking demonstrations by Maryland chefs Boris and Berj Ghazarian and live music by Armenian a cappella trio Zulal.

The Castle reopened in spring 2026 during a temporary pause in its ongoing revitalization, according to a July 28 Smithsonian announcement. Lisa Sasaki, the Smithsonian's deputy undersecretary for special projects, said in that announcement that the institution appreciated "the overwhelming support for this exhibit and enthusiasm for all of our 250th programming."

Sept. 7 also marks the final day for two other Smithsonian exhibitions. The Renwick Gallery's "State Fairs: Growing American Craft" features more than 240 artworks, including a 700-pound butter cow sculpture. The Hirshhorn's "Basquiat × Banksy" show presents two major paintings and 20 smaller works, the first time either artist has appeared at that museum.