Lake Alexandrina is a coastal freshwater lake located between the Fleurieu and Kangaroo Island and Murray and Mallee regions of South Australia, about 100 kilometres (62 mi) south-east of Adelaide. The lake adjoins the smaller Lake Albert and a coastal lagoon called The Coorong to its southeast, before draining into the Great Australian Bight via a short, narrow opening known as Murray Mouth.

Lake Albert, also known by its Ngarrindjeri name, Yarli, is a notionally fresh water lake near the mouth of the Murray River in South Australia. It is filled by water flowing in from the larger Lake Alexandrina at its mouth near Narrung. It is separated on the south by the Narrung Peninsula from the salt-water Coorong. The only major town on the lake is Meningie. Lakes Alexandrina and Albert are together known as the Lower Lakes.