Simplify the following text for a Grade 12 native English-speaking person.
Original: This Akkadian occupation was succeeded by an occupation during the third dynasty of Ur , and the constructions of Ur-Nammu , the great builder of temples , are superimposed immediately upon those of Naram-Sin .
Simplified: This Akkadian occupation was succeeded by an occupation during the third dynasty of Ur , and the constructions of Ur-Nammu , the great builder of temples , are on top of those of Naram .