Neither. The Persian Gulf is a geographical feature. A gulf is an area of sea partially surrounded by land.
That is Iran.
A gulf is the name of an inlet of the sea - so water.
I believe that is the Strait of Hormuz going into the Gulf of Oman.
a portion of the ocean partly surrounded by land - as in the Persian Gulf
That is the Arabian peninsula.
Fertile Crescent.
That is the Arabian Peninsula.
That is central Iraq.
gazza strip
It is a silty, shallow delta.
Assyrian Empire.