Disaster of Aral Sea The Aral Sea was once the fourth largest inland sea in the world. About, a million years ago from now the northwestern part of Uzbekistan and southern Kazakhstan were covered by a massive inland sea. This sea was formed when all the waters retreated from a big land; they left a broad plain that contained highly saline soil. Due to the retreating of water many ancient remains were disappeared. The only remnant that remained was a big inland sea which was the Aral Sea. The Aral Sea was an inland salt water sea, one odd thing about this sea is, there was no channels connected to the sea.