Eglarest, along with Brithombar, was one to the two great havens built in Beleriand during the Years of the Trees. Eglarest was the southernmost of the two and stood at the mouth of the River Nenning.

Eglarest was fortified after the return of Morgoth but eventually fell, along with Brithombar late in the First Age.

When the forces of the Valar arrived in Middle-earth to take on Morgoth, they won one of the first battles when they took back Eglarest.