You enter the Haskell Free Library and Opera House in Derby Line, Vermont, but if you venture toward the nearby bookshelves, you'll find yourself in Stanstead, Quebec. The building sits directly on the border between the U.S. and Canada, and its unusual location is no accident. It was commissioned by Martha Stewart Haskell and her son Colonel Horace Stewart Haskell in dedication to Mrs. Haskell's late husband, Carlos. Carlos Haskell had been a prominent merchant in the border community, so the building was erected as a gift to the Americans and Canadians who called the area home. Its spot on the border gives it a few remarkable claims to fame: since the library books and circulation desk are on the Canadian side but the entrance is on the U.S. side, the building has been called the only library in the U.S. with no books. Likewise, the opera-house stage is in Canada and its seats are in the U.S., so it's the only U.S. opera house with no stage. And though the building was conceived as a gift to both countries, the border on each side of the building is fenced off. The only way to walk freely between Derby Line, Vermont and Stanstead, Quebec is to visit the library.