The Haskell Free Library and Opera House straddles the US / Canada border. Most of the books are on the Canadian side (of course) but the main entrance is on the US side. See the black line in the photo. Park your car on the Canadian side, walk into the US, then into the library again... (I assume the US border guards are very tolerant and a lot of cameras are hidden around the area. Several yards and houses in the area (Derby Line VT, Stanstead QC) also straddle the line).