The forest on the banks of the river Esgalduin that formed the southern and greater part of the kingdom of Doriath, and within which lay the halls of Menegroth.
Notes
1
The fact that Region is also an English word can give rise to confusion over the pronunciation of this forest's name. In fact this ElvishRegion is pronounced quite differently from the English word 'region'. In particular, the e is pronounced short (as in 'red'), and the g is pronounced hard (as in 'garden').
2
The forest's name comes ultimately from regorn, a word in the Doriathrin language for a holly-tree (and thus Region shares the etymological roots of its name with the later land of Eregion or Hollin).