Keno's memory

The long tunnels underneath the Capital of Docrem were not difficult to find. For many years, those tunnels had been used as a route of commerce and transport for merchants and travelers from the outside towns, other Estates and several foreign countries.

The great architects from recent years had enhanced the tunnels and protected them with new columns and better materials,  even more careful designs to widen the space of the hallways and made them safer.

If one were to carefully look at those structures, they will easily know that the one creating them was a genius. A genius with thoughts of greatness.

They may have found the tunnels before they started the construction of the City and the Great Royal Castle. However, the connection to other Kingdoms or the black markets didn't seem like something they wanted. Someone seemed to have locked the entrances to the tunnels, the hidden ones on purpose. Why would someone do that? What was their plan?