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
Architectural conservation life and preserving the integrity of architectural character, such as form and style, and/or its constituent materials, such as stone, brick, glass, metal, and wood. In this sense, the term refers to the "professional use of a combination of science, art, craft, and technology as a preservation tool" and is allied with - and often equated to - its parent fields, of historic environment conservation and art conservation. In addition to the design and art/science definition described above, architectural conservation also refers to issues of identification, policy, regulation, and advocacy associated with the entirety of the cultural and built environment.