A park which has much of its footpaths and coasters underground.
Wacky Warren is the tenth scenario listed in the Loopy Landscapes expansion pack for RollerCoaster Tycoon, as well as the seventh scenario listed in the Ivory Group (White) on RollerCoaster Tycoon Classic. You have two roller coasters already built that are partially underground and can help you with reaching your goal. Like the description says, most of the pathways are underground.