The old Pension Building has long been the National Building Museum. It has a freize along the entire façade that portrays the Union soldiers for whom it was made. They’re classically-inspired, and have been maintained well.
Many great exhibits are inside, and SEGD–an organization to which I belong–used to have its offices there. One unique feature inside: the stairs inside are shallow to allow horses to climb them with minimal trouble.
Tags: national building museum, segd