Flanked by two powerful nations, the English Channel has long been one of the world's most important maritime passages. Yet for most of its history, crossing was a dangerous prospect. Engineers proposed numerous plans for spanning the gap, including a design for an underwater passage more than twice the length of any existing tunnel. Alex Gendler details the creation of the Channel Tunnel. [Directed by Studio Kimchi, narrated by Addison Anderson, music by Aurélien Vieira Lino].