Boston Athenaeum's fractional address

The Boston Athenaeum, an independent library and cultural institution founded in 1807, is located at the unusual street number 10 1/2 Beacon Street. That fractional address and the building's modest entrance contribute to visitors sometimes missing the library while walking Beacon Hill. The Athenaeum houses rare books, artworks, and a historic reading room that are primarily accessible to members and researchers, with limited public hours.