  We describe the Fundamental Neutron Physics Beamline (FnPB) facility located
at the Spallation Neutron Source at Oak Ridge National Laboratory. The FnPB was
designed for the conduct of experiments that investigate scientific issues in
nuclear physics, particle physics, astrophysics and cosmology using a pulsed
slow neutron beam. We present a detailed description of the design philosophy,
beamline components, and measured fluxes of the polychromatic and monochromatic
beams.
