An atoll ( /ˈætɒl/ or /æˈtɒl/) is a coral island (or islands) that encircles a lagoon partially or completely.

Read more about Atoll:  Usage, Distribution and Size, Formation, United States National Monuments

Other articles related to "atoll":

Sport In Tokelau - Healthcare and Education
... Each atoll has a school and hospital ... in Apia and a Chief Clinical Advisor who moves from atoll to atoll as required to assist the doctors attached to each hospital ...
Ant Atoll
... Ant Atoll is a small atoll lying off the west coast of Pohnpei in the Federated States of Micronesia ... Along with the nearby Pakin Atoll, these islands constitute the Senyavin group of islands ... The atoll is no longer inhabited ...