Al-Istablat was a large walled structure located to the south of Samarra. The northern part consisted of a palace that overlooked the Tigris, while the southern area contained a number of housing units. A long outer wall enclosing al-Istablat and the surrounding area was also built. Al-Istablat is believed to be al-'Arus, one of the palaces built by al-Mutawakkil.