Saint Martin Island is a small island with a surface area of only 3 km2 in the northeastern Bay of Bengal. It is about 9 km south of the Cox's Bazar-Teknaf peninsula's tip and is Bangladesh's southernmost point. Chera Dwip is a small neighboring island that is separated at high tide. It is at the mouth of the Naf River, approximately 8 kilometers (5 miles) west of Myanmar's northwest coast.
The island was once an extension of the Teknaf peninsula for millennia. However, the southernmost portion of the aforementioned peninsula became an island and was cut off from the Bangladesh mainland when some of the peninsula became submerged. The Arabian merchants who gave the island the name "Jazira" established the first settlement on the island 250 years ago. St. Martin Island was given to the island during British occupation in honor of Mr. Martin, the Deputy Commissioner of Chittagong at the time. Probably because one or more of the Arabs, whose names were unknown, were saints. "Narikel jinjira"[3], which means "Coconut Island," and "Daruchini Dwip," which means "Cinnamon island," are the island's native names. It is Bangladesh's only coral island.