The walls were built from bottom to top one level at a time. Workers pressed and packed in the materials into sections ranging from 50 and 70 cm in length that were each held together temporarily by wooden boards. Once the material was settled, the wooden restraints could be removed and the process was repeated on top of the previously completed level. This process of initial wooden scaffolding often leaves traces in the form of multiple rows of little holes visible across the face of the walls. In many cases walls were covered with a coating of lime, stucco, or other material to give them a smooth surface and to better protect the main structure.