According to Nevada Appeal, The History Channel recently recorded a segment on Sinatra’s former Cal Neva Lodge for their program “Cities of The Underworld.” Set to air sometime in December of January, the segment highlights the network of private tunnels beneath the lodge that were designed to allow high-profile guests and Sinatra himself to get around the facility without necessarily having the transit the casino floor.

Cities of The Underworld airs Monday evenings at 9PM on The History Channel.