Scattered throughout the north of Naggaroth there are many fortified Watch Towers. They overlook the Chaos Wasteland and provide a first line of defence against the incursions of Chaos Warbands. Since their creation the Watch Towers have proved invaluable, the Chaos Warbands that cannot be destroyed by the Watch Towers garrisons are slowed down and harried until a larger Dark Elf force from one of the cities can be sent to deal with them.
The Dark Elves have many enemies, real and imagined. The nemesis the High Elves are reside in Ulthuan. The armies of the Empire and the Dwarves have constantly ruined their plans for the Old World. The local tribes of Orcs and Goblins are constantly rebelling against their rightful masters. Skaven tunnels reach into the heart of Naggaroth. The enigmatic Lizardmen to the south block the expansion of the Dark Elves borders. But none of these enemies pose a threat greater than the forces of Chaos.
Chaos Warbands have sometimes joined with Dark Elves in the past although the two sides have fought many bloody battles against each other. The forces of Chaos want the Elves of Ulthuan destroyed as much as their bloodthirsty kin so uneasy alliances have been created over time. The two allies have fought each other over many times though. Both the forces of Chaos and the Dark Elves are cruel, treacherous and pure evil so it is not surprising that they have tried to annihilate each other. Both sides view each other as pawns in their master plans: the Dark Elves as effective troops in the reclamation of their homeland and Chaos as extra manpower until they are powerful enough to destroy them.
The power of Chaos is constantly growing. The Witch-King knows that soon the forces of the Dark Gods will be powerful enough to try to conquer the earth as they have tried in past times. Malekith regards Chaos as a great threat, requiring constant monitoring against treachery. He knows that soon the two sides will turn against each other, one will be utterly destroyed while the other will eventually gain dominion over the entire world.
The towers are designed for defence, they are not as stunning as the Dark Elf cities. While they look like Dark Elf cities they are much smaller. The Watch Towers consist of a small tower surrounded by high walls. They are not meant to be permanent dwellings, only temporary living quarters for the garrisons stationed there.
The Watch Towers of Naggaroth are used as training facilities for the Dark Elf army. Troops are rotated in from each of the Dark Elf cities. This ensures that the Dark Elf troops are kept in a constant state of readiness for battle. In addition to regular Dark Elf troopers some elite regiments such as Cold One Knights and Witch Elves are occasionally sent to Watch Towers to provide a better defence against invasions and to curb their bloodlust. The garrisons also house many fast moving troops such as Scouts and Dark Riders to explore the borders and send back any word of invasion to the Dark Elf cities.