J.R.R. Tolkien’s The Children of Húrin is set primarily in Beleriand.
Beleriand is a region of Middle-earth during the First Age, long before the events of The Hobbit and The Lord of the Rings. The story follows Túrin Turambar and his sister Niënor, whose lives are shaped by the curse placed on their father, Húrin, by the Dark Lord Morgoth.
The narrative includes major First Age locations such as Dor-lómin, Doriath, Nargothrond, and Brethil. Its tragic events form part of Tolkien’s larger mythology about the wars against Morgoth, Sauron’s predecessor and master. Much of Beleriand is destroyed or submerged at the end of the First Age during the War of Wrath.
The Children of Húrin was published as a standalone book in 2007, edited by Christopher Tolkien from his father’s existing writings. It is therefore not a newly invented sequel, but a reconstructed and expanded presentation of an older legend from Tolkien’s fictional history.