Nan Elmoth was a forest in East Beleriand east of Doriath, south of the River Celon, and north of Estolad. One of the two roads that the Dwarves took from Blue Mountains towards Beleriand passed near Nan Elmoth. There the trees grew to be the tallest and darkest in Beleriand, blocking the sun entirely from the forest floor.
Maps
Melian met Thingol in Nan Elmoth, and stayed motionless for years while the trees grew around them. When they woke up, they founded the realm of Doriath. Nan Elmoth was held to be part of Doriath, and Eöl the Dark Elf paid Thingol with the black sword Anglachel as a fee for living there. Eöl dwelt with his wife Aredhel, their son Maeglin, and a household of servants. Eöl's house consisted of a smithy and dim halls and was located in the middle of Nan Elmoth around fifteen miles from the northernmost edge where the Celon River ran.