The mysterious knowledge surrounding the transportation and placement of megalithic structures of the past eludes contemporary building practices. Walking Assemblyre-introduces the potentials of that ancient knowledge to better inform the transportation and assembly of future architectures. If a brick is designed for a single hand, and a concrete masonry unit (CMU) is designed for two, these massive masonry units (MMU) unshackle the dependency between size and the human body. Intelligence of transportation and assembly is designed into the elements themselves, liberating humans to guide these colossal concrete elements into place. Structures that would otherwise rely on cranes or heavy equipment can now be intelligently assembled and disassembled with little energy. By using variable density concrete, the center of mass of the object is calibrated precisely to control the stable, but easy motion of the elements. This ensures that these massive elements successfully walk and assemble into place, creating the possibility for a crane-less tilt up construction method and turning our building sites into spectacles of play.