Šayḫ Qubbah or Sequba is an abandoned settlement on the right bank of the Tigris. Apart from the ruins of recent habitation, the site features traces of ancient fortifications. Some scholars have posited that this was the location of the Roman fortress of Castra Maurorum, surrendered by the emperor Jovian to the Persians in 363. This is not certain.
Anthony Comfort, The Roman Frontier with Persia in North-Eastern Mesopotamia: Fortresses and Roads around Singara, Oxford, 2023: 79-84.