Surrounding the wall was a moat formed by the Euphrates River. The river passed through the center of the city; but at the place it entered the city, there were large gates extending down into the water.
Kuzunguka ukuta kulikuwa na shimo kubwa dhidi ya wavamizi lililofanywa na Mto Frati. Mto ulipita katikati ya mji, lakini kwenye sehemu ulipoingilia mjini, kulikuwa na malango makubwa yakienea hadi majini.