Endor region, located in the old site where the Helcar Sea was, enclosed, except in the east, by a formidable natural wall that made up the Ephel D\xfaath and the Ered Lithui. These mountain ranges came to be less than 100 meters from each other at the Pass of the Spectra and less than two kilometers in Carach Angren, forming between them a huge "bowl" known as Ud\xfbn, a desolate valley of volcanic origin.

After you, the highlands of the country were occupied by the Gorgoroth Plateau, in whose northern area was the Orodruin volcano and, on a spur of the Ered Lithui, the tower of Barad-D\xfbr, from where Sauron, the Lord of the Rings , tried to enslave the entire Middle Earth and its people. In the lowlands the Nurn and Lithlad regions were located, as well as the inland sea of ​​N marrnen, just a small trace of what was the Helcar Sea. Enclosing the whole complex, as has already been said, the Ered Lithui and the Ephel D\xfaath constituted an insurmountable natural defensive wall, which could only be addressed by the Morannon in the northwest, by Imlad Morgul in the west and by the Nargil Pass, In the southern arch. Only the plains of Rh\xfbn and Khand, in the east, opened freely before Mordor, although that turned out to be much worse for its inhabitants than for the Black Country itself.

The origin of Mordor must be placed at the end of the First Age, when the War of Cholera occurred. As in all previous clashes between the Powers, in the subsequent cataclysm the land underwent dramatic changes that included the sinking of some areas and the lifting of others. The geological forces were incited to superlative levels and this, of course, had an impact on all the regions of Arda.

In the genesis of Mordor the following events could have happened: As a result of the collapse of the Iron Mountains, seismic forces of such magnitude were unleashed that the southernmost lands, which occupied the Helcar Sea, suffered an elevation, which caused the drainage of the inland sea in Belegaer. These seismic forces aroused intense volcanic activity on a large scale, which caused the rapid formation of the surrounding mountains. Surely those same forces, in another geological start, returned to level the ground, preventing the last remains of Helcar (what would be the seas of Rh\xfbn, on the border of these lands with Rhovanion, and N\xfbrnen, in Mordor) to finish pour into the ocean.