Christmas Underground returns this holiday season beginning this Thursday, Dec. 1, at Ruby Falls every Thursday thru Sunday until Dec. 18. Then the holiday attraction will be offered daily from Dec. 19–23 from noon to 8 p.m.Visitors will take a magical adventure deep within the heart of Lookout Mountain where children discover a secret underground passage to see Santa.One highlight is the decorated gemstone mines in this unique setting 26 stories underground. Adventurers go on a journey past the Northern Lights and Sugar Plum Fairy Village, into a tunnel (optional), through an ice cave and to the North Pole where Santa awaits.