This fortress was occupied and further built upon until the close of the Parthian period , about AD 250 ; but under the succeeding rule of the Sassanids it in its turn fell into decay , and the ancient sanctuary became , to a considerable extent , a mere place of sepulture , only a small village of mud huts huddled about the ancient ziggurat continuing to be inhabited .
Under the rule of the Sassanids Nippur fell into decay , and the ancient sanctuary became only a little village of mud huts huddled about the ancient ziggurat .