Fornost Erain:

The capital of Arnor after Annúminas, Fornost was once captured by the forces of Angmar. Though retaken, it was abandoned as in that same year came the end of the North Kingdom as such. After abandonment, Fornost Erain was known as Deadmans Dike.

Fangorn Forest:

The eastern remnant of the forests covering Middle-Earth in the Elder Days, Fangorn forest, and possibly the Old Forest, were the only remains of the forests of the Elder Days. Fangorn Forest was certainly the only one with the Shepherds of the Trees still surviving. Also called the Entwood, in Rohan, because of the Ents, who were the Shepherds of the Trees. Fangorn Forest was an obviously old forest, where there were some places that the original darkness still had not been lifted according to Treebeard.

Firien Wood:

The wood surrounding the Halfirien, which was also known as Amon Anwar, the Hill of Awe.

The Hobbit
The Lord of the Rings
The Silmarillion
The Complete Guide to Middle-Earth by Robert Foster
The Unfinished Tales