Below average adventure with a lot of FX , all of them being recreated by means of traditional effects . This one deals with two friends Webber (Andrés Alexis) and Fernando (Juan Carlos Gabarda) who meet a moribund Indian called Sinoqui (Francisco Pardo) who tells about an Inca treasure , he gives them a map and a ¨Quipu¨ as tracks to find it . Later on , they set out in chase by submarine , looking for a fabulous treasure , while wandering throughout various countries and suffering a lot of dangers and risks , such as : floods , falls , bat attacks , tortuous caves , dense jungles and inhospitable locations . They team up with a mestizo called Manuel (Juan Carlos Lee) and a veteran adventurer , Morgan (the only known actor : Frank Braña , a famous support player from Spaghetti/Paella Western) . The group aboard a submarine crossing the Pacific Ocean to the Amazons , South America . Being pursued by a dangerous band led Carnot (John Legget) who kidnap Marcella (Cristina Cavallaro) , Webber's girlfriend . And the end takes place the moving confrontation between the likable adventurers and the nasty hoodlums . This is a humdrum adaptation based on Emilio Salgari novel from a screenplay by the filmmaker himself . Atmospheric as well as ridiculous adventure movie in ¨Indiana Jones¨ style contains action , shootouts, bemusing scenes and being made in low-budget . The picture belongs to a trilogy written/produced/directed by Juan Piquer formed by 1999 El Escarabajo De Oro or The gold beetle , 1994 La Isla del Diablo or Devil Island and Manoa, La Ciudad De Oro or the city of gold (1999) . It has some lousily made scenes , including primitive special effects , adding floods , explosions , phosphorescent fish and a submarine scale model , toy-alike , taken from ¨The Rift¨ film . Using "older technique" FX that seem little bit cheesy , such as transparency , matte paintings, rubber-suited enemies , reverse-footage to create certain images , Golden Maquettes posing as the city of gold ; all of them were made by the craftsman director himself , Juan Piquer . You will watch it and think it is either awful , hilarious , a masterpiece, or all three . It's a slight fun with embarrassing images , naive special effects , horrible musical score , campy set decoration and ridiculous art direction . Although critics do not appreciate much this picture ; however has a kind of loopy , Ed Wood quality that must be endured to be totally considered . The fable is sometimes silly and laughable , though a few naif effects and action are regularly made . Some illogical parts in the plot are more than compensated for the excitement provided by the adventure rush and the light enthusiasm provided by Juán Piquer .The motion picture was lousily directed by Juán Piquer and considered to be one of his worst yarns . He was born in Valencia , location where he often shot his films , in fact ¨Manoa¨ was shot in Algar De Palancia , Buñol , Cortes De Pallás, Júcar , La Vall d'Uixó , Montanejos , Yátova, Millares , Comunidad Valenciana . Juan , who goes by "J.P. Simon" on foreign releases , began in films as a writer and assistant director and continued his career by making short films and documentaries . Juan has produced and directed "exploitation" pictures for two decades running , while not hits during original run , his films became limited successes as bad-good flicks . He was one of the main directors of the Spanish horror boom in the 70s and 80s specially for his quartet of horror films as ¨Escalofrio¨, ¨Slugs¨ , ¨Cthulhu Mansion¨ and his greatest success and immensely popular ¨Pieces¨ . Juan owns his own studio and created and/or designed many of the simple and primitive special effects sequences you see in any of his many imaginative undertakings . Piquer , who recently passed away , was a good craftsman who realized a lot of amusing as well as entertaining films . Juan Piquer who was director of the Mostra of Valencia (Spain) , displayed a professional career and specialized on all kind of genres as Terror , Sci-fi as The rift , The new Extraterrestres, and Supersonic man deemed to be one of the worst films of cinema history . And made some adaptations about Jules Verne novels : "Fabulous Journey to the Center of the Earth" , "Mystery on Monster Island" . While his films have been universally panned by the prestigious reviewers, they have a kind of quality that must be endured to be utterly appreciated .