Great Colonnade at Apamea columns display two main designs: a plain one, and the distinctive spiral-flutes. Archaeologist Jean Lassus argues that the former dates back to the Trajanic period, while the latter to that of Antoninus Pius. The colonnade's porticoes were paved with extensive mosaics along the full stretch of the colonnade. Under the Byzantine Emperor, Justinian I, several parts of the colonnade were restored. The street was narrowed to by adding a sidewalk on either side. Several stretches of the street had their Roman pavement replaced with a new pavement made of squared blocks of limestone. The new pavement also covered a completely
Society of Architectural Historians of Architectural Historians". The name was shortened to its current form a decade later. SAH is currently the largest academic organization in the field of architectural history in the US. As part of its mission to "advance knowledge and understanding of the history of architecture, design, landscape, and urbanism worldwide", the Society publishes several works, most noticeably the "Buildings of the United States" series, as well as a newsletter and the "Journal of the Society of Architectural Historians" (). In addition, in association with the University of Virginia, the Society is developing an online encyclopedia of architecture called SAH Archipedia.