The cave leading to Morgana's land was the Bronson Canyon Cave near Griffith Park. Being so close to several Hollywood studios made Bronson Canyon and its caves a favorite filming location since 1919. Over 70 movies and TV shows have used it, most notably as the entrance to the 1960s Batcave.
The fifth MacGyver story in which MacGyver experiences an alternate reality (dreams, visions or near death experience) while sleeping, unconscious, injured or dying.
Previous episode "Holy Rose" bad guy Christopher Neame reappears in this episode as bad guy Sir Duncan.