The Spire is the oldest building in the city, built by the void elves in a long forgotten age. It is built from an unknown material that is impossibly strong and extremely conductive of magic. Following the fall of Vel'kira, the city of Kelletirandia fell into ruins. An unstable blast from the Spire devastated the surrounding area and rendered it an uninhabitable wasteland for a thousand years.
The first people to re-colonize the Spire area were the dwarves, who built their city underground and avoided the slowly-recovering barren lands on the surface. Eventually, they were joined in the underground by the gnomes.
After millennia, humans came and built a city on the surface, but they stayed close to the water and avoided the immediate Spire area. They refused to touch the Nexus complex in the center of the peninsula. It wasn't until the high elves arrived that the Spire area got truly re-colonized.
The high elves considered the Spire to be sacred, a great shrine to the sun, and built close to the Spire even within the Nexus complex itself. They did not realize that the Spire was still spewing out magical radiation that was causing mutations in their children. The dwarves and gnomes, living underground, did not experience this to the same level, and the humans were flexible and did not mind.
The high elves, on the other hand, slowly took up wide-scale culling of their children. At first they only went after the children born with deformities, feeling it a mercy to kill any child born blind or deaf. In modern times, this had expanded to include even children born with the wrong hair color. The other people of Kelletirandia found this practice monstrous, although they could do little about it due to the power of the high elves. They did occasionally manage to rescue a mutant child and raise them as their own in the underground, or smuggle them out of the city.
The underground became a sewer when the high elves decided to use it to dump their waste and filth. Only the poor and stubborn continued to live there. Few high elves ever went down there.