There aren't any large cities in the Southern Part of the Arabian Peninsula due to the Arabian Desert.
Arabian Peninsula is the largest Peninsula in the world and is made up of Saudi Arabia, Yemen, Bahrain, Qatar, Oman, Kuwait, UAE. It also includes some parts of Iraq and Jordan.
However, in modern times, Saudi Arabia covers more than 60% of the land area.
The area has always been sparsely populated, especially in the south as you go deeper into the Arabian desert.
It is a harsh climate and a difficult terrain, where it is not easy to grow food. Hence, the area is mostly made up of small villages and towns.
