This paper examines the "complexity" of space in Agoras by analyzing their architecture using image-processing technology. Agoras were central to the lives of Western European people and can be called the starting point of Western European civilization. Image processing technology was used to perform the initial restoration of the architecture and city shape. Each building in the 3D model of the plaza was then constructed, centering on the formation of the Agora. The box-counting method was used to determine the relationship between the shadow image and the fractal analysis of the 3D plaza composition. This was applied in the fractal analysis of the changes in the arrangement of the facilities from generation to collapse.