A explicação que encontrei na encicopledia Britannica:
" Lagash, the modern Telloh one of the most important capital cities in ancient Sumer, located midway between the Tigris and Euphrates rivers in southeastern Iraq. The ancient name of the mound of Telloh was actually Girsu, while Lagash originally denoted a site southeast of Girsu, later becoming the name of the whole district and also of Girsu itself. "