Atoll remains of an ancient atoll as a hill in a limestone area is called a reef knoll. The second largest atoll by dry land area is Aldabra with 155 km². The largest atoll in terms of island numbers is Huvadhu Atoll in the south of the Maldives with 255 islands. In 1842, Charles Darwin explained the creation of coral atolls in the southern Pacific Ocean based upon observations made during a five-year voyage aboard from 1831 to 1836. Accepted as basically correct, his explanation involved considering that several tropical island types—from high volcanic island, through barrier reef island, to atoll—represented
Ari Atoll islands in the Atoll designated for tourist resorts. Each island resort is self-contained with accommodation and recreational facilities such as tennis court. Scuba diving is the most popular tourist activity in the Maldives. The diving in Ari Atoll is extensive and is often defined by location within the atoll, either North or South. The main tourist resorts were Ari Beach, Halaveli, Maayyafushi, Twin Islands Resort, and Dhoni Mighilli Ari Atoll Ari Atoll (also called Alif or Alifu Atoll) is one of the natural atolls of the Maldives. It is one of the biggest atolls and is located in the west