Stanford Linear Accelerator Center

World’s longest building cost £1.6bn to build and takes 40 minutes to walk across

World’s longest building cost £1.6bn to build and takes 40 minutes to walk across A vast industrial building in California is considered the world’s longest, stretching so far that it takes around 40 minutes to walk its full length A gigantic two-mile-long structure has long been regarded as the world's longest building — and it is so vast that experts say the curvature of the Earth must be taken into account when measuring it. The Klystron Gallery at SLAC National Accelerator Laboratory,...