Skandelion

1: A major subterranean network of tunnels, shafts and corridors. Skandelion is located where Perdigor rises from the Dagdor Massif. Skandelion is thought to be a former dwarven realm now deserted for unknown reasons. The name was applied to the underground cave complex by the discoverers wrongly thinking it to be Skandelion (2). See Dwalin's Gate. 
Map I-s.
2: The legendary re-built capital city of the Third Empire . The legends are thought to be a distortion of the history of Palmyria. Usually Skandelion is located underground with an entrance up in the mountains. In rarer versions Skandelion is a beautiful garden-like city in the midst of an elven realm (such as Lacre-Cai or in the Great Forest). 
Description':
An enormous underground network and caves located in the Dagdor Massif. The main entrance to the south is guarded by the now derelict dwarven fortress Dwalin's Gate, but other means of ingress can be found. Supposedly, Skandelion stretches from Dwalin's Gate to Miralandor, and goes all the way down to the elemental plane. According to legends, it served as a kind of underground road for the dwarves. At first, It was not meant as mining area in itself. But gold or some other valuable ore was found, and the dwarves started mining. Delving ever deeper, the dwarves encountered some subterranean evil. Perhaps drow, perhaps mind flayers, no human really knows, and the dwarves will not tell. The mining dwarves were somehow corrupted, and the other dwarves had to fight their own kin, in the end closing the tunnels to the north to shut off their former brethren.What remains is considered a treasure chest by some, and a death trap by others. It is a place many adventurers seek. 
The name Skandelion was originally the mythical name given to the mysterious new capital of the Third Empire. According to that myth the wealthy people of Suada moved to Skandelion to found a new empire just before the fall. In some versions, this new city was underground in Dagdor. When the tunnels were discovered, the name Skandelion was given to them, even though it had nothing to do with the dwarven tunnels.