Beneath the island of Trophaeum, there is a massive underground city which features all forms of Air Treck technology, including scrapped ideas and prototypes. This is where all ideas are tested, and where all unreleased technology is stored and utilized to avoid the public eye. It is also the location that powers the 72 Trophaeum Towers across the world, and can be linked directly to each one through the planet's mantle. Here, the legendary individuals that have been given the epithet "progenitors" have a place to call home. The city is otherwise occupied by scientists and the like, all of whom have been given a new, underground life for the purpose of testing and maintaining the structural balance of the city. As for why... only the progenitors have been told.