Withered Heath
The Withered Heath was a dragon-infested valley in the eastern Grey Mountains in northern Rhovanion.
Other version of the legendarium
In one of the earliest versions of the legendarium, the Withered Heath was the name of the Heath of the Sky-roof, a location of Tol Eressëa near Tavrobel, after a great battle between Men who came to the island.
In the manuscript of The Hobbit, Bladorthin (the pre-cursor to Gandalf) says that the Withered Heath is "where the Great Dragons used to live".
Description
The Withered Heath was a long narrow valley in the eastern part of the Grey Mountains, where they forked into two thin ranges. On the floor of this long east-west valley between the mountains was a heath, burned and blackened by its inhabitants, being the breeding-ground of dragons.