Aventura em Forgotten Valley por Glyn Frewer:)
This young adult fiction story is set in South America. Five Children of varying ages get separated from their local guide when a cave in occurs in the passage they just explored. While trying to find another way out the children discover a lost valley where time stopped in the era of Dinosaurs. Their journey and trials make for a very exciting and entertaining adventure as they battle dinosaurs, and work to survive on their trek back to their families.