This is really fascinating. Technology has brought us to the point of being able to virtually reconstruct a building just from data obtained about the building, itself, remnants found, information about the time period, and even demolitian records.
The method involves compiling all the historical, literary and graphical documents about the monument as well as information obtained from archaeological remains. Unknown aspects are determined from information obtained from other similar buildings. And at the end all the information is used to create 2D and 3D computer graphics of the different parts of the building, by using graphic design and animation software.
This virtual 3-D reconstruction might even be able to give us insight on how to construct future buildings.