Venue: Haskell Free Library and Opera House
Address: 93 Caswell Avenue
Town: Stanstead, US

The Haskell Free Library and Opera House (French: Bibliothèque et salle d'opéra Haskell) is a Victorian building that straddles the Canada-United States border, in Rock Island (now part of Stanstead), Quebec, and Derby Line, Vermont, respectively. The Opera House opened on June 7, 1904, having deliberately been built on the international border. It was declared a heritage building by both countries in the 1970s and 1980s. The library has two different addresses and postal codes: 93 Caswell Avenue, Derby Line, Vermont, 05830 and 1 rue Church (Church Street), Stanstead, Quebec, J0B 3E2. The building was a gift of "Mrs. M. M. Haskell and her son, Col. H. S. Haskell", referring to Martha M. Haskell (née Stewart; 1831-1906) and Horace Stewart Haskell (1860-1940) of Derby Line, Vermont. It was built at a reported cost of approximately $25,000 in 1904 ($895,833 in 2025). It was designed by architect James Ball in the Queen Anne Revival style. The first floor houses the book collection and reading rooms and a 500-seat theater occupies the second and third floors. The library collection and the theater stage are located in Stanstead, Quebec, but the main entrance and most theater seats are located in Derby Line, Vermont. Because of this, the Haskell is sometimes called "the only opera house in the U.S.A. with no stage.” A thick black line runs diagonally across the public spaces to mark the Canada-United States border. The library, located at ground level, has a collection of more than 20,000 books in English and French and is open to the public five days a week. French and English books are organized separately because of different language conventions in the direction of printing titles on spines: English books have titles written top-to-bottom, and most French books bottom-to-top. Membership in the library is free, restricted to persons who live within "a 30 mile or 50-kilometer radius of the library", which must be confirmed through documentation, such as a utility bill,