St. Martin is generally known as “Narikel Zinzira” in Bengali, means 'Coconut Island’ and this is the only coral reef island in Bangladesh. It is a small island in the north eastern part of the Bay of Bengal, created the southernmost part of our country. It is about 8 km west of the northwest coast of Myanmar, at the mouth of the Naf River. It is only 8 sq. Kilometre in size. Experts separate this island into three parts. Northern part is called Narikel Jinjira. It is 2. 134 km long and 1, 402 m wide. The southern part is called Dakkhin Para by the local and its length and width are successively 1929 m and 1890 m. The middle part which known as Maddhapara locally. The length and width respectively 1524m and 518m.The island is very much ingenious with vast biological variety such as existing fauna and flora Coral, Mollusk, Fish, Amphibian, Turtle, Snail, Bird and Mammals. Besides above coconut tree is the important cash crop.