Ver en Cuevana. Deep in the Amazon rain forest, there is a lost subterranean city. The place was built by Vikings who crossed the Atlantic Ocean and ventured up the Amazon River, and shelters a mysterious treasure. In order to find the secret location, Bárbara and the children Riacho and Manhã will have to face many challenges. Vicious snakes and dangerous pendulum blades are only the beginning of our heroes' adventures.