In Western countries it is called the Persian Gulf, in most Arab countries it is called Arabian Gulf.
The length is 1,000 km, and the maximum width is 370 km. To the south, the coastline is flat, while the coast on the Iranian side is mountainous. The temperatures are high, and the salt level is as high as 40%, which results from evaporation higher than the supply of fresh water.
The main freshwater source is from Iraq, through the Shatt al-Arab, the confluence of the rivers Euphrates, Tigris, and Karun.
Through the Strait of Hormuz, the gulf is connected to the Gulf of Oman and the Arabian Sea.
There have been serious incidents that have affected the environment of the gulf in recent years. While oil spills from the heavy traffic of oil tankers over years have been serious enough, oil spills from 1983, during the Iran-Iraq War, and in 1991, during the Gulf War, have been catastrophic.
The area of the Persian Gulf has slowly decreased during the last 6,000 years when most of Kuwait and lower Iraq were part of the total basin. This process continues still as sediment from the Shatt al-Arab enlarges the delta area and reduces the area of the gulf.