A few miles northeast from the massive underground spaces of SubTropolis, and past a large FedEx distribution complex, is another Kansas City area underground business park called Rush Creek Underground. It is relatively new, and is being marketed for light industrial development, with over a million square feet of developable space. Located adjacent to an active limestone quarry, it operates as an open pit, which is the way limestone is mined today, as opposed to the underground method that created all the mines around Kansas City into the 1950s.