Rings : Sea... — A Shadow Of The Pastthe Lord Of The

This is the other major inland sea, located far to the east. It's often associated with the Easterlings and remained largely mysterious in the main books.

The Lord of the Rings: Sea of Longing or The Sundering Seas . A Shadow of the PastThe Lord of the Rings : Sea...

Alternatively, you might be referencing the "sea-longing" that many characters (like Legolas) feel as the Third Age ends. This is the other major inland sea, located far to the east