When satellites spot a strange, 2,000-year-old structure in Wales, some suspect a secret connection to King Arthur; using modern-day technology and ancient texts, experts investigate new leads that could point to the mythical Round Table.

Adam Ruben, Becca Peixotto, Bronwyn Agrios, Carlo Muñoz, Carolyn Finney, Daniel Sayers, David Krueger, Eleanor Spicer Rice, George Kourounis, Guy Walters, Haley Chamberlain, Jennifer Lee Jellicorse, Karen Bellinger, Katie Paul, Keri Leigh Merritt, Kevin Hymel, Lindsay Moran, Mark Horton, Martin K.A. Morgan, Patrick Hunt, Randy Cerveny, Rob Nelson, Roland Kays, Sara Carter, Tracy Fanara, Trevor Albertson