A strait is a narrow waterway that connects two larger bodies of water. It can develop after water breaches an isthmus, which is a narrow strip of land connecting two bodies of water. A strait can also be caused by water overflowing onto eroded land.
Many straits are strategically important. One such example is the Strait of Hormuz. At 21 to 60 miles wide, it connects the Persian Gulf with the Arabian Sea and the Gulf of Oman. It is one of the major passages through which oil is transported out of the Middle East, and Oman and Iran share territorial rights to it as of 2015.