Mystic Caverns and Crystal Dome in Harrison. Tickets cost $9 for 2 Adult (age 13+) and $7 for 2 children (4-12 years old). Tickets may be sold individually. http://mysticcaverns.com. Phone: 870-743-1739 or 888-743-1739. Tickets expire 12/1/18. Purchase tickets at KTLO, Classic Hits and The Boot on 620 Highway 5 North in Mountain Home, Arkansas. Call 870-425-3101 for more information.