Denver International Airport is preparing to open portions of a mysterious underground tunnel system that has long been plagued by conspiracy theories. Officials announced plans this week to convert sections of the airport’s underground baggage tunnels into pedestrian walkways connecting concourses A, B and C. The tunnels, which have long fueled speculation involving secret bunkers, "lizard people" and underground military facilities, will become an alternative route for passengers traveling between terminals. Currently, travelers primarily move between concourses using the airport’s underground train system. Denver Mayor Mike Johnston acknowledged the airport’s unusual reputation while discussing the project.