The attempted identification of the source of asphalt which was used in the building of the old city of Babylon (whether it was from the Qayarah or Heet locations) is discussed. Thermogravimetry, differential thermogravimetry, as well as carbon-13 and proton NMR spectroscopy were employed as the main analytic tools in this investigation. The results indicated that the most probable source of Babylonian building asphalt was from Heet. -- AATA