The Lighthouses, as the Empire of Tears once called them, are massive towers assembled on 4 key focal points of the continent’s ley-lines. These points are essentially magnets for magical energy of the planet, drawing it slowly into itself and causing great reservoirs of power to form deep within the planet. With the Lighthouses the Empire sought to draw this power for their own benefit. The great towers were setup at the edges of their territory supplying what seemed like infinite power for their great projects, however as their war with the Vashal carried on they found that even this was not enough.
They first turned to the fiends that dwell outside of the world, waiting for a chance at entry. They became dark, and soon the Lighthouses reflected this change, their power grew and their form twisted, but even this was not enough.
It wasn’t until the South tower almost fell that they discovered the true power of the ley-lines, they didn’t just channel magic energy, they channeled all energy in the area. As the defenders of the tower perished, the Archmage atop it became more and more powerful.