Forgotten Realms - Rites of Ascension
Sea of Fallen Stars
The Sea of Fallen Stars, also known as the Inner Sea, is the largest inland body of water in Faerûn.The name of the sea is from the origin story which states that the Inner Sea formed when the four Inner Seas merged together, coinciding with the loss of entire continents from earthquakes, fires and windstorms due to a star sent by deities to punish the titans’ arrogance. Other theories have sprung up maintaining it was actually the eggs of the first dragons raining down onto the planet.
Tens of thousands of dragon eggs did hatch soon after the event, though the real reason for the destruction was the primordial Asgoroth the World Shaper hurling an ice moon down to Abeir-Toril’s surface.
Sarrukh accounts dated around -31000 DR mention a “changing of the stars” in relation to this event. Few know what this really signified.Regardless, this event, known as the Tearfall caused a climate shift that wiped out the batrachi civilization.
(The above info was provided by http://forgottenrealms.wikia.com/wiki/).
Recently there have been rumors of a dark tower located in the eye of a terrible storm and of deep mists and an island of people with very odd clothing sighted in the Sea. These rumors have yet to be confirmed or denied.