This is officially the world's largest QR code. Carved into a field of maze in Alberta, Canada, it measures 28,760 square metres and links to the Kraay Family Farm website.
Photographs of it -- all invariably taken at an angle unless the photographer happens to be a satellite -- don't seem to work particularly well with QR readers, which makes this dumber than every other QR code. The only people able to make use of it are helicopter pilots. So, that's worth it? [Kraay Family Farm via CBC]