The Falas was an area on the west coast of Beleriand, south of Nevrast. The River Brithon and the River Nenning ran into the sea here. The Falathrim, Sindarin Elves ruled by Círdan, dwelt here and built the havens of Brithombar and Eglarest. In F.A. 65, Finrod built the tower of Barad Nimras ("White Horn Tower") on a cape of the Falas between Brithombar and Eglarest, to watch for attacks from the sea by Morgoth.

The Falas only occasionally enters into the events of the First Age; in the First Battle of Beleriand, Morgoth's host overran the Falas and besieged the two havens, but lifted the siege in order to in the Second Battle. The Havens of the Falas were finally destroyed in F.A. 473, and Círdan's people fled to the Mouths of Sirion and the Isle of Balar.

The word falas means "surfline, sea-shore" in Sindarin, deriving from the root PHAL ("foam").

BRITHOMBAR

Brithombar was the western of the two Havens of the Falas, at the mouth of the River Brithon, from which it took its name. It was occupied by the Elves of the Havens until it was invaded and destroyed in F.A. 473 along with its twin, Eglarest.

Brithombar comes from the name of the river Brithon, which means "pebbly".

EGLAREST

Eglarest was the southern of the two Havens of the Falas that lay at the mouth of the River Nenning on the western coasts of Beleriand. The northern haven was called Brithombar. They were founded during the Years of the Trees by Círdan. Upon the cape west of Eglarest Finrod had built Barad Nimras. The Havens lasted until they were taken by Morgoth in F.A. 473.

It has been suggested that the name means "Ravine of the Eglain". Cf. the Noldorin word rhest and Imladris.

Source: tolkiengateway