Nobody knew how old Nexus City was. A hundred and seventy-five years ago, when the tunnels were rediscovered, Nexus City had been in place, the buildings empty, silent, and dusty. The general consensus among forensic archeologists was that the dust was approximately two thousand years old. Some theorized that it was no coincidence that this period more or less coincided with the rise of Emperor Heinlein.
There was also evidence that small groups had access to doorknobs and over the centuries had periodically explored the tunnels and Nexus City. Be that as it may, the city's revival corresponded to the general rediscovery of the Strange Worlds' tunnels by citizens from Blue. As more and more doors were opened, and as more and more visitors moved from door to door and tunnel to tunnel, Nexus City's importance as a commercial, cultural, academic, and athletic center grew.
And so it was that a dot-com businesswoman from Blue, a caravaneer from Yellow, and a magic shop owner from Red met and decided that what the new Nexus City really needed was a shopping mall. Archivolts had been in operation ever since. There were a thousand mottos, designed for ten thousand different kinds of customers: "One hundred sixty two years in one location;" "Just ask;" "The best mega-mall in Blue is actually in Nexus City."
A number of business plans were tried, and eventually the owners settled on a combination of off-the-rack display floors, an auction house, and a high-value concierge service. The current facility took up approximately two square blocks and was nineteen floors high. A nearby warehouse was almost twice as large. Branch offices were located in thirty realities in all three tunnels.