The Great Bahama Bank is a winding limestone sea mound that underlies a large part of the nation of The Bahamas. On the western side, it starts at Bimini and stretches to the Berries. To the south Andros, the largest Bahama island group, takes up a large chunk of the Bank. Two deep-sea features cut into the Bank, effectively bisecting it: The Northeast Providence Channel separates the Berry Islands from New Providence (Nassau) and the Tongue of the Ocean separates Andros from the Exumas. On the other side, the Great Bahama Bank includes Nassau and the Banks that stretch to the Exuma Cays and Long Island.