Fortunately for Hormuzan, Shushtar was well fortified due to the rivers and canals that surrounded it on almost all sides. One of them was known as Ardashiragan, named after the first Sasanian king Ardashir I (r. 224-240). Another known as Shamiram, named after the legendary Assyrian Queen Semiramis. The last one mentioned was known as Darayagan, named after the Achaemenid king Darius I (r. 550–486 BCE). There are several versions of the how the city got captured; according to al-Tabari, during the siege, an Iranian defector named Sina (or Sinah) went to al-Nu'man and pleaded for his life to be spared in return for helping him how to show a way into the city. Al-Nu'man agreed, and Sina told him the following thing; "attack via the outlet of the water, and then you will conquer the city."