Dol Amroth; the Elf-haven of Edhellond, was on the borders of this region (the extent of those borders is unclear, but the townships of Ethring and Linhir possibly also bordered Belfalas)
A promontory and fief of southern Gondor, lying between the mouths of the Rivers Morthond and Gilrain. Its chief city lay at Dol Amroth on its western coasts.
Notes
1
It seems that this region was settled by an independent group of FaithfulNúmenóreans in the Second Age, before the establishment of Gondor by the sons of Elendil. We have little specific detail about these early settlers, but they gave rise to the noble line of the Princes of Belfalas, and were apparently the ancestors of the Princes of Dol Amroth.
2
Falas is a well-established Elvish word meaning 'shoreline' or 'coast', especially one washed by surf. The Bel- element of Belfalas' name is more difficult to interpret, and indeed Tolkien himself seemed unsure of its origins. In some sources it is interpreted as Sindarin, meaning 'steep' or 'sheer' in reference to its cliffs. Elsewhere the name is seen as coming from an obscure ancient name Bêl for a part of this region, though that name may in turn have been influenced by Elvish.