One island in this body of water includes the locales of Darren and Alzour. In addition to containing Tarut Island, it bordered the early Dilmun and Lakhmid civilizations on its south shore, and the port of Siraf was a notable Sassanian port which served its north shore. Its west end is marked by the Shatt al- Arab, while its east end is separated from the Gulf of Oman by the Strait of Hormuz. Qatar juts into, for 10 points, what sea, containing 
One island in this body of water includes the locales of Darren and Alzour. In addition to containing Tarut Island, it bordered the early Dilmun and Lakhmid civilizations on its south shore, and the port of Siraf was a notable Sassanian port which served its north shore. Its west end is marked by the Shatt al- Arab, while its east end is separated from the Gulf of Oman by the Strait of Hormuz. Qatar juts into, for 10 points, what sea, containing the Tigris delta, which shares its name with the former name of Iran?
One island in this body of water includes the locales of Darren and Alzour.
Persian Gulf [prompt on Arabian Gulf; do not accept The Gulf]