The parts of Middle-earth we see in the books are empty, because Sauron has been fighting a war against the Numenoreans and their allies for 2000 years. He has

The parts of Middle-earth we see in the books are empty, because Sauron has been fighting a war against the Numenoreans and their allies for 2000 years. He has also been winning the war. Northern Eriador, roughly the area between Shire and Rivendell, used to be Arnor. The northern counterpart to Gondor was first weakened in civil wars and then destroyed by the armies of the Witch King. People don't return to the area, because they believe the ruins of the cities are haunted. The Misty Mountains are infested with orcs. Few people live near the mountains, except in Dunland in the south. Anduin runs between the Misty Mountains and Mirkwood. Few people are willing to live near them. Particularly because Sauron built his fortress in the southern Mirkwood and spent most of the last 2000 years there. Further south, the lands west of the river are near Lorien and Fangorn, and people are afraid of the beings living in those forests. On the eastern side, the lands between Mirkwood and Mordor are either barren or were ruined in the battles at the end of the Second Age. Osgiliath, Minas Anor/Tirith, and Minas Ithil/Morgul used to be three great cities of Gondor. However, Minas Ithil was lost and Osgiliath abandoned long ago. At the end of the Third Age, most of the population of Gondor lives in the coastal areas protected by the White Mountains and Minas Tirith. Pelargir is a major port near the mouth of Anduin, and Dol Amroth is another major city. We know little of the lands to the east and to the south, except that they were capable of sending large armies against Gondor.