Why had Mesopotamians built Mari? French archeologist solves mystery of ancient Mesopotamian city purpose-built in desert for metallurgical industry. By Annick Benoist - PARIS The mystery of an ancient Mesopotamian city has finally been lifted after 25 years of meticulous work by a French archaeologist who has revealed it was one of the first "modern cities", purpose-built in the desert for the manufacture of copper arms and tools. In a new book entitled "Mari, the Metropolis of the Euphrates", Jean-Claude Margueron said the third millennium BC city, in modern day Syria, was "one of the first modern cities of humanity....