Baratal limestone
... that the Baratal limestone in Russia may be one of the oldest atolls in the world?
... that the <b id="mwATI"><a href="./Baratal_limestone" id="mwATM" rel="mw:WikiLink" title="Baratal limestone">Baratal limestone</a></b> in Russia may be one of the oldest <a href="./Atoll" id="mwATQ" rel="mw:WikiLink" title="Atoll">atolls</a> in the world?