In LOST CONTINENT (1951) with Cesar Romero we have Major Joe Nolan (Cesar Romero) as the head of a mission to an uncharted part of the South Pacific to retrieve an atomic rocket that went off course and vanished. Their search plane then crashes on a remote tropical island with towering cliffs and volcanoes. They find a lone native girl, Acquanetta (Tarzan and the Leopard Woman, 1946), who indicates something fell from the sky onto a forbidding plateau that dominates part of the island. The party reaches the top despite numerous obstacles and deaths. At the top, they discover a lush jungle inhabited by dinosaurs. They have found a lost world of prehistoric dinosaurs and vast radioactive uranium fields, so powerful that they cause rockets and planes to go off course.